CA1327092C - Functionalized polymers and process for the preparation thereof - Google Patents
Functionalized polymers and process for the preparation thereofInfo
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- CA1327092C CA1327092C CA000573024A CA573024A CA1327092C CA 1327092 C CA1327092 C CA 1327092C CA 000573024 A CA000573024 A CA 000573024A CA 573024 A CA573024 A CA 573024A CA 1327092 C CA1327092 C CA 1327092C
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- polymer
- copolymer
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- hydrogenated
- hydrogenation
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F8/00—Chemical modification by after-treatment
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F8/00—Chemical modification by after-treatment
- C08F8/04—Reduction, e.g. hydrogenation
Abstract
A B S T R A C T
IMPROVED PROCESS FOR MODIFYING
UNSATURATED POLYMERS
Process for the preparation of a functionalized hydrogenated polymer by (a) catalytically hydrogenating an unsaturated polymer, (b) after the hydrogenation is completed and before the hydrogenation catalyst is deactivated, contacting the hydrogenated polymer with a functionalizing agent, and (c) recovering the functionalized hydrogenated polymer; and a functionalized selectively hydrogenation copolymer of a monoalkenyl-aromatic hydrocarbon and a polyolefin in which the functional groups are predominantly incorporated in the polyolefin portion and separated from any residual unsaturation by at least three carbon atoms.
IMPROVED PROCESS FOR MODIFYING
UNSATURATED POLYMERS
Process for the preparation of a functionalized hydrogenated polymer by (a) catalytically hydrogenating an unsaturated polymer, (b) after the hydrogenation is completed and before the hydrogenation catalyst is deactivated, contacting the hydrogenated polymer with a functionalizing agent, and (c) recovering the functionalized hydrogenated polymer; and a functionalized selectively hydrogenation copolymer of a monoalkenyl-aromatic hydrocarbon and a polyolefin in which the functional groups are predominantly incorporated in the polyolefin portion and separated from any residual unsaturation by at least three carbon atoms.
Description
FUNCTIONALIZED POLYMERS AND PRO OESS FOR
THE PREPARATION THEREOF
The invention relates to a process for the preparation of a functionalized hydrogenated polymer.
The invention also relates to a functionalized, selectively hydrogenated copolymer.
Polymers containing ethylenic unsaturation are well known. When these polymers are prepared by the addition polymerization of a polyunsaturated ole~in, the unsaturation may be contained within the palymer backbone or pendent therefrom dependent upon the addition mechanism. For example, when l,3 butadiene is the monomer, the unsaturation will be internal when the addition is l,4 and external when the addition is l,2.
As is also known, both of these unsaturations are relatively unstable and are subject to both thermal and oxidative degradation. In a diolefin homopolymer or a random copolymer, degradation of an internaI double bond ~imply reduces the average molecular weight of the product. When such degradation occurs in a block copol~mer, however, degradation o~ an internal double ~ bond may be far more serious even to the extent of des~roying desired pol~meric properties. Degradation of an external unsaturation, on the other hand,~in all such polymers simply reduces the polymers elastomeric propertie~. It is well known to hydroyenate addition polymers containin~ both internal and pendent unsaturation to avoid such degradation. Hydxogenation o~ such polymers is known from, for example, U.5.
- 1 3~ ~9~
~ - 2 -: patent specifications Mos. 3,419,365; 3,644,58B;
4,400,478; 4,578,429 and Re. 27,145.
The incorporation of one or more functional groups into a polymer containing unsaturation to improve its properties for various uses is also well known. Methods for incorporating functional groups into such polymers are known from, for example, ~.S. patent specifications Nos. 3,135,716; 3,150,209 and ~,409,357. When tha ethylenic unsaturation in the initial polymer is completely saturated via hydrogenation, however, it has not, heretofore, been possible to incorpora~e functional groups into the polymer via these techniques. Moreover, when the starting polymer is a copolymer of a vinyl aromatic hydrocarbon and a polyolefin, and the residual unsaturation initially in the polyolefin portion of the copolymer has been : substantially completely saturated via hydrogenation, the functional yroups will be incorporated exclusively into the aromatic portion of the copolymer. Functional groups incorporated into the aromatic portion of the copolymer may not, however, be a~ reactive as those incorporated into the polyolefin portion of the copolymer. Moreover, ~unctional groups incorporat~d into the aromatic portion of a copolymer may not, in all cases, result in the same end-use properties.
: While it is, at least, theoretically possible to first incorporate one or more functional groups into a - : polymer and then to hydro~enate the functionalized polymer, attempts to do this have not been succes~ful to date primarily due to poisoning of thQ hydrogenation ; catalyst by tha functional group. Attempts to ~; ~ accomplish such hydrogenation have also been hampered by the potential for reductive hydrogenation and by : conversion of the functional group during hydrogenation.
. , ~3~70~2 As indicated hereinbefore, it is also, theoreti-cally, possible to first hydrogenate the polymer product and to then metalate the hydro~enated product to facilitate functionalization of the hydrogenated pol~mer. Metalization of a hydrogenated copolymer of a conjugated diene and a monovinylarene is known from U.S. patent specification No. 4,145,298. According to this specification, however, the metalated sites are then used to graft organic nitrogen compounds so as to produce a viscosity index improver~ To the extent that the residual unsaturation in the diolefin portion of the pol~mer is substantially completely hydrogenated, however, the metal sites will be incorporated princi-pally, if not exclusively, in the aromatic portion of the polymer. Such metalization, i.e., in the aromatic portion of the polymer generally requires the use of more metalating agent than does metalization of resi-dual unsaturation in the diolefin portion of the polymer and, generally, requires the use of one or more metalization promoters such as an amine. Moreover, hydroyer.ation followed by metalization increases the number of steps required to accomplish the end result.
In the light of the foregoing, it is clear that it has, heretofore, not been possible to produce a ~unctionalized hydrogenated copolymer of a monoalkenyl aromatic ~ydrocarbon and a polyole~in wherein the ~unctional groups are predominantly in the polyolefin portion o~ the polymer, at least not when the functional groups are two or mor~ carbon atoms removed fxom any r~sidual unsaturation. Noreover, it has not, heretofor~, been possible to producs a functionalized, hydrogenat~d polymer without accomplishing each in a diqtinctly separate step. The need, then, for a functionalized, hydrogenated copolymer of a monoalkenyl aromatlc hydrocarbon and a polyolefin wherein the ~ 1 3~ 7~J92 functional group~ are at least predominantly in the polyolefin portion of the copolymer and the need for a process wherein such a copolymer may be prepared with a reduced number of steps is believed to be readily apparent.
It is now been discovered that the foregoing and other disadvantages of the known functionalized thermo-plastic elastomeric polymers can be overcome or at least significantly reduced.
It is, therefore, an object of the present inven-tion to provide an improved functionalized thermoplastic elastomeric polymer and a process for making said improved functionalized thermoplastic elastomeric polymer. It is another object of this invention to provide such a functionalized thermoplastic elastomeric pol~mer which will exhibit the impxoved properties o~ a hydrogenated, functionalized thermoplastic elastomeric polymer. It is still another object of th~s invention to provide a procsss for preparing such an improved functionalized thermoplastic elastomeric polymer which requires a reduced number o~ steps. It is still a further object of ~his invention to provide an improved functionalized hydrog~nated thermoplastic polymer wherein the functional groups are predominantly, if not exclusively, in the elastomer portion of said polymer.
The foregoing and othex o~jects and advantages will becoms apparent from the description set forth herein--after.
Accordingly, the invention provides a process for the preparation of a functionalized hydrogenated polymer which process comprises the following ~tep~:
step a: contacting an unsaturated polymer with hydrogen in the presence of a hydro~enation cakalyst obtained by combining an alkoxide or a carboxylat~ o~ a metal of Group 8 and an .
alkyl or hydride of a metal of Group la, 2a or 3a of the Periodic Table of the ElPments;
step b: aftar the hydrogenation of step (a) is completed and before the hydrogenation catalyst is quenched or otherwise deactivated, contacting the hydrogenated polymer with a functionalizing agent; and ctep c: recovering the functionalized, hydrogenated polymer.
The invention also provides a functionalized, selectively hydrogenated copolymer which comprises monoalkenyl aromatic hydrocarbon monomer units and ; polyolefin monomer units wherein the functional groups are predominantly incorporated in the polyolefin portion of the polymer and separated from any residual unsaturation by at least three carbon atoms. Following the contacting with the functionalizing agent, the hydrogenation catalyst may be deactivated and the polymer product recovered as a crumb.
As indicated herein~efore, the present invention relates to a homopolymer or copolymer comprising a polyolefin which has been hydrogenated and functional-ized and to a process for hydrogenating and functional-izing such a polymer. As also indicated hereinbe~ore the hydro~enation and functionalization are, in effect, accomplished in a cingle step by first contacting the polymer with hydrogen in the pres~nce o~ a hydrogena-~ tion catalyst obtained by co~bining an alkoxide or ; ~ carbo~ylate of a Group 8 metal o~ the Periodic Table of the Ele~ents and a metal hydride or alkyl and than with a ~unctionalizing agent. As also indicated supra, the hydrogenated polymer will be contacted with said func-tionalizing agent be~ore the hydrogenation catalyst is quenched or otherwi~e deactivated.
., !~
,~
1327~92 In general, any polymer containing unsaturation, such as that imparted through the polymerization o~ a polyolefin, may be hydrogenated and functionalized by the process according to the present invention. Such polymers include homopolymers of polyole~ins, particu-larly conjugated diolefins and copolymers of one or more polyolefins, particularly conjugated diole~ins, and one or more other vinyl monomers which homopolymers and copolymers may be prepared via anionic polymerizà-tion with an organo alkali metal catalyst or initiator.Such polymers also include polyolefin homopolymers and copolymers prepared via polymerization in the presence o~ a ~ree radical initiator and polyolefin homopolymers and copolymers prepared via cationic initiation.
In general, the polyolefin homopolymers and co-polymers which are hydrogenated and functionalized in the process according to the present invention will ha~e a weight average molecul-ar weight within the range from about 2,000 to about 450,000. The copolymers which may be hydrogenated and functionalized may be random, block or tapered. In general, and when the copolymer contains one or more vinyl monomers dif~erent from the polyole~in, the polyolefin will comprise from about l to about 99% by weight of the polymer.
As indicated hereinbefore, unsaturated polymers which may be hydrogenatad and functionalized by the proce~s according to the present invention are ela-stomers comprising monomeric units of at least~one polyole~in, particularly a conjugated diole~in. In general, the unsaturated polymer may contain monomeric units o~ at least one polyolefin, particularly a conjugated diolefin, containing from 4 to about 12 carbon atoms such as, for example, l,3-butadiene, isoprane, pipe~ylene, methylpentyldiene, phenylbuta-diene, 3,4-dimethyl-l r 3-hexadiene and 4,5-diethyl~
3-octadiene.
Preferably, the unsaturated polymer will comprise monomeric units of at least one conjugated diene containing 4 to 8 carbon atoms per molecule. As also indicated hereinbefore, the unsaturated polymeric elastomer which may be hydrogenated and functionalized by the process according to the invention may be a copolymer of one or more of the aforementioned polyolefins and one or more other monomers. Other monomers which may be used include vinyl-aryl compounds such as styrene, various alkylstyrenes such as for example, a-methylstyrene, 1- and 2-vinylnaphthalene, 1-, 2- and 3-vinyltolu~ne and paraalkoxystyrenes in which the alkoxy group has in the range o~ from 1 to 20 carbon atoms, for example parametho~ystyrene.
As indicated hereinbefore, the unsaturated polymers which may be hydrogenated and functionalized with the process according to the present invention may be prepared via any of the ~nown techniques. These technigues include bulk, emulsion, suspension and solution polymerization. Moreover, any of the known initiators may be used. Such initiators include ~ree radicals and both anionic and cation polymPrization catalysts~ As is also known, elastomeric diolefin homopolymers and copolymers are most generally produced 25 Yia either an emulsion technigue using a free radical initiator or in solution using an anionic initiator.
Emulsion polymerization is, generally, accomplished at a temperature within the range of from about 20 to about 90 C and at a pressure within the range from about 1 to about 10 bar while solution pol~merization with an anionic initiator is generally carried out at a temperature within the range ~rom about -100 C to abouk 200 C at a pressure within the range from ahout 1 to about 50 bar.
~ 3 2 7 ~ 9 ~ 63293-2964 Unsaturated homopolymers and copolymers which may be ..
hydrogenated and functionalized by the process according to the present invention include those homopolymers and copolymers described in United States patent specifications Nos. 3,135,716;
3,150,209; 3,496,154; 3,498,960; 4,145,298 and 4,238,202.
Unsaturated polymers which may be hydrogenated and f~mctionalized by the process according to the present invention also include the block copolymers prepared in accordance with the process described in United States patent specifications Nos. 3,231,635;
3,265,765; 3,322,856; 4,391,949 and 4,444,953. Particularly useful block copolymers are those bl.ock copolymers having one of the general formulae:
BX-(A-B)y Az; AX-(B-A)y~Bz; x y z ~n [AX,~(B-A)y~Bz,~n Z wherein A represents a polymer block of an alkenyl-substituted aromatic hydrocarbon and B a polymer block of a conjugated diene; x and z are, independently, integers equal to 0 or 1 and y is a whole number from 1 to 25; x' and z' are, independently, integers ranging from 0 to the value of y; n is a whole number from 3 to 15, as determined by gas permeation chromatography (GPC) on a polystyrene scale and Z represents a residue of a coupling agent of a star-shaped block copolymer, such as a polyalkenyl coupling agent.
In general, the unsaturated polymers to be hydro-genated and functionalized by the process according to the present invention will be dissolved in a suitable solvent and then contacted with molecular hydrogen in the presence of a hydrogena-` - 1327092 tion catalyst obtained by combining a Group 8 metal carboxylate or alkoxide and a hydride or an alkyl of a metal of Group la, 2a or 3a of the Periodic Table of the Elements. The Periodic Table of the Elements is that shown on the inside of the cover of "~andbook of Chemistry and Physics", 61st edition (1980-1981), CRC Press Inc. Hydrogenation catalysts of this type are described in, for example, United States patent specifications Nos.
3,541,G64; 3,595,942 and 4,028,485. Of the Group 8 metals, those of the so-called Iron Group; viz. iron, cobalt and nickel are particularly effective. Of the Group la, 2a and 3a metals, lithium, magnesium and aluminum are particularly effective. A key to selecting a metal of Groups la, 2a and 3a for use in the hydrogenation catalyst is, of course, the stability of the metal alkyl formed by reaction of the initial hydride or alkyl with the polymer. In this regard, it has been ~ound that the aluminum polymer alkyl is the least stable of those formed with the metals tested. It is, then, important that the subsequent contacting with a functionalizing agent be accomplished relatively quickly after hydrogenation when a catalyst comprising aluminum is used.
The lithium polymer alkyl on the other hand is very stable. As a result, contacting with the functiona]izing agent after hydrogena-tion may be delayed for relatively long periods.
In general, the hydrogenation will be accomplished in a suitable solvent at a temperature within the range from about 20 C to 150 C at a hydrogen partial pressure below 70 bar and contacting between the polymer and the hydrogen will be maintained _ g _ n~
~ 3 2 7 0 9 ~ 63293-296~
for a nominal holding time within the range from about 10 to about 1000 minutes. Suitable solvents for use during the hydrogenation inclu~e, but are not limited to, hydrocarbons such as paraffins, cycloparaffins, : - 9a -n ~:i i327~92 alkyl-substituted cyclopara~fins, aromatics and alkyl-substituted aromatics containing ~rom about 4 to about lO carbon atoms per molecule. Suitable solvents include for example, benzene, toluene, cyclohexane, methylcyclohexane, n-butane, n-hexane and n-heptane.
While the applicant does not wish to be bound by any particular theory, it is believed khat both the Group 8 metal and the metal selected from Groups la, 2a and 3a will react with the ethylenic unsaturation contained in the polymer to form polymeric alkyls during the hydrogenation. The ~roup 8 metal polymer alkyls are, however, relatively unstable and do not become involved in the subsequent functionalization reaction. The Group la, 2a and 3a metal polymer alkyls are, however, significantly more stable and the metal site, if not removed or otherwise rendered inactive durlng hydrogenation, will be availab~e for subsequent reaction with the functionalizing agent. In any case, the functional group ultimately will be bonded to a carbon atom which initially was bonded to another carbon atom through a double bond. As a result, the functional group will be separated from any residual unsaturation by at least three carbon atoms. While still not wishing to be bound by any particular theory, it is also believed that the amount of functionalizing agent that may be incorporated is, in effect, propor-tional to the number of ~roup la, 2a and 3a metal atoms actually contained in the hydrogenation solution; or at least incorporated into the polymer during hydxogena-tion. The amount of ~unctionalizing agent ultimatelyin~-orporat~d can, then, be controlled by controlling the amount of Group la, 2a and 3a metal added as a catalyst component and by controlling the extent of hydrogenation at least to the point that the ethylenic unsaturation is not completely hydrogenated. In any case, polyolefin portion of the polymer may be substantially completely saturated, if desired, partly due to hydrogenation and partly due to reaction with the functionalizing agent.
In general, the hydrogenation will be a~complished such that from about lO to about 99% of the initial unsaturation in the polyolefin portion of the polymer becomes saturated during hydrogenation. At least a portion of the remaining unsaturation may, then, contain a metal atom which will be available for subsequent reaction with the selected functionalizing agent.
As indicated hereinbefore, the hydrogenated or partially hydrogenated polymer is next functionalized by contacting the same with a suitable functionalizing agent after the hydrogenation step has been completed or at least staxted and before the hydrogenation catalyst is quenched or otherwise deactivated.
Functionalizing agents which will react with the partially hydrogenated polymer include, but are not necessarily limited to for example, carbon dioxide, ethylene oxide, aldehydes, ketones, carboxylic acids, carboxylic acid salts, carboxylic acid esters, halides, epoxides, sulphur, boron alkoxides, isocyanates and various silicon compounds. In general, contacting of the hydrogenated polymar and the functionalizing agent will be accomplished at a temperature within the range o~ from 20 C to 150 C and at ~ nominal holding time within the range from about l to about 200 minutes.
Once the functional group ~r groups have been incorporated, the polymer may be recovered and then used in any o~ those applications for which the polymer is known to be u~eful. Alternatively, and where the functional group was incorporated for the purpose of enabling grafting or other reaction, the grafting or other reaction could bs compl2ted.
12 ~ 3 2 70 g2 In general, from about O.l to about 5% of the ; initial unsaturation in the polyolefin portion of the polymer will become saturated as a result o~ reaction with a ~unctionalizing agent, thereby incorporating from about O.Ol to about 5 wt~ functional groups, based on final product. Moreover, the functionalization (hydrogenation) operating conditions actually contemplated for use ln the process according to the invention have been selected so as to insure that a predominant amount (more than 50%) of the . functionalizing agent is incorporated into the ; polyolefin portion of the polymer. Further, these operating conditions can be even more restricted, as in the preferred embodiment, to insure that substantially all of the functionalizing ag~nt is incorporated into the polyole~in portion of the polymer. As used herein, the recitation "substantially all" is intended to mean that at least 95% o~ the functionalizing agent i5 incorporated into the polyole~in portion of the polymer.
In a preferred embodiment of the present : invention, an unsaturated block copolymer comprising at le~st one diolefin block and at least one of a vinyl--substituted aromatic hydrocarbon block will be selectively hydrogenated and then cantacted with carbon dioxide to incorporate functional groups. The block copolymer will be prepared using the method described in U.S. patent specification No. 3,231,635. In a most pr~erred embodiment o~ the present invention, the block copolymer will comprise three blocks and may be : represented by the ~eneral formula A-B-A wherein A and B are, respectively, polymer blocks of an alkenyl-sub-stituted aromatic hydrocarbon and a diolefin. In both ~he prefarred and most pre~erred embodiments, the alkenyl-substituted aromatic hydrocarbon blocks will ~L327~2 have a weight average molecular weight within the range from about 2,000 to about 50,000 and the diolefin blocks will have a number average molecular weight within the range from about 2,000 to about 150,000. In the most preferred embodiment of the present invention, the alkenyl-substituted aromatic hydrocarbon will be styrene and the diole~in will ~e a conjugated diolefin, particularly either butadiene or isoprene.
In both the preferred and most preferred ~mbodi-ments, the block copolymer will be hydrogenated justafter its production in solution with an anionic ini-tiator, particularly a butyllithium compound. The hydrogenation will be completed in the presence of a hydrogenation cataly~t prepared by combining nickel octoate and sec-butyllithium. The molar ratio of nickel to lithium in the catalyst will be within the range from about 0.1:1 to about 0.6:1. The catalyst will be used at a concentration sufficient to provide from about 50 to about 500 parts per million (ppm), by weight, o~ nickel in the polymer cement.
In the preferred and most preferred embodiment , the hydrogenation will be accomplished with a hydrogen partial pres~ure in the rang of from 7.9 to 56.2 bar and at a temperature within the range from 40 to 80 C.
Contacting between the polymer and the hydrogen will be maintained for a pariod of time within the range from about 60 to about 240 minutes. In the pre~srred and most preferred embodiment from about 80 to about 98% of the initial unsaturation in the diole~in polymer will be saturated with hydrogen during hydrogenation.
A~ter the hydrogenation reaction has been completed but before the reaction is quenched or the catalyst otherwisa deactivated, and in a preferred embodimant, the polymer will be contacked with C02 at a C2 partial pressure within the range fxom about 1.7 to `` ~ 327~92 ~ - 14 -about 35.5 bar and at a temperature within the range from about 20 to about 80 C, preferably 40 C to 80 C. Contacting o~ the polymer with C02 will be continued ~or a period of time within the range ~rom about 1 to about 120 minutes. The contacting of the polymer and C02 will be accomplished in the presence of the same catalyst as was used during the hydrogenation.
In both the preferred and most pre~erred embodiments from about 0.~ to about 2.0~ of the initial unsatura-tion contained in the diolefin portion of the copolymer will be saturated as a result of reaction with the functionalizing agent.
After contacting of the polymer with carbon dioxide is completed, the hydrogenation and functionalization reaction~ may be quenched or the catalyst otherwise deactivated using known techniques.
Reaction with an aquPous sulphuric acid solution is, however, particularly preferred following contacting with carbon dioxide since this will convert the metal salt group to the carboxyl group. Following quenching or deactivation of the hydrogenation catalyst, the polymer may be separated and recovered as a crumb and then used in any of the applications ~or which a carboxylated pol~m~r would be useful. The polymers produc~d in the preferred and most preferred embodiment are particularly us~ul a~ a modifier in sheet moulding and bulk moulding compo~itions.
The following Examples ~urther illustrate the invention.
ExamE~
In this example, 88 g o~ a styrene-butadiene diblock copolymer were hydrogenated and then contacted with carbon dioxide (C02) in the prasence of a catalyst con~isting o~ the raaction product of nicXel octoate and sec-butyllithium, whic~ had been combin~d in a ~327~92 Ni:hi molar ratio o~ 1:6. In the diblock polymer, khe styrene blocks had a molecular weight of 37,000 and the butadiene blocks had a molecular weight of 63,000. The hydroganation was started at a temperature o~ 40 C and with a hydrogen partial pressure of 45.8 bar. The hydro-genation was completed in the presence of su~icient catalyst to provide 70 ppm. by weight of nickel based on block copolymer solution. The catalyst was added in 3 increments. A*ter each increment was added, an exotherm was noted. After the first increment was added, the hydrogenation temperature rose to 52 C, after the second increment was added the hydro~enation temperature ro~e to 65 C and a~ter the third increment was added thP hydrogenation t~mperature rose to 74 C.
The hydrogenation was then continued for about 180 minutes then at a temperature of 80 C. After complekion o~ the hydrogenation, $7.5 per cent of th~
olefinic unsaturation had been hydrogenated. The extent of hydrogenation was determined using an ozone titration technique. The hydrogenated diblock wa~
metalated. Without further treatment, the freshly hydrogen~ted, metalated block copolymer was functionalized by reaction with an excess of C02.
Following the ~2 contacting, 1% by weight (wt) H2S04 in water was added to the mixture to deactivate and separate the hydrogenation catalyst. Following this deactivation and separation, the polymer was recovered as a crumb using an excess of isopropyl alcohol.
To demonstrate ~hat the recovered product was a carboxylate polymer, solution viscosity expariments were per~ormed which showed that the polymer was iono-meric. Spe~ifically, a 6 wt~ solution o~ the product polymer in cyclohexane was separated into 3 aliquots o~
25 g each. The first, hereinafter solution 1, was a control and was not alter~d; the second was treated 13~7~
with 1 ml of acetic acid to minimize ionic association arising from polymer bound-CO~- moieties; and the third was treated with 5 g Mg(OH~2, to maximize the ionic association o~ the polymer -C02- sites. The three solutions were allowed to equilibrate for 2 days before the viscosity measurements were made using a Brook~ield Viscometer. The measured viscosities of solutions 1, 2 and 3 were 68, 55 and 72 cP, respectively. As expected, the solution with the maximum ionic interaction, solution 3, was more than 30% more viscous than the solution wherein ionic interaction had been minimized, i.e., solution 2.
For purposes of comparison, the viscosity of 6 wt%
solution o~ an identical hydrogenated diblock copolymer which had not been contacted with a functionalizing agent was 18 cP. Treatment of this solution with both acetic acid and Mg(OH)2 gav~ solutions having viscosi-ties of 16 cP a~ter 2 days.
Example 2 In this example, the procedure of Example l was repeated exc2pt that the hydrogenation temperature and holding time were reduced so as to produce a diblock copolymer having only 23~ of the olefinic unsaturatio~
hydrogenated. A 1200 g aliquot of the resulting polymer cement was then combined with 8.4 g o~ a ~unctionaliza-tion promoter; viz., N,N,N',N'-tetramethylethylenedi-amine and then contacted with C02 in the same manner as described in Example 1. An aliquot af the reco~ered carbo~ylated polymer was then dissolved in tatrahydro- -furan and titrat~d with standardized methanolic XOH to a phenolphthalein endpoint. This titration revealed 0.02 wt% polymer bound carboxylic acid; i.e., pendent -C02H groups.
An infrared (IR) spectrum of the carboxylated polymer had a signal at 1715 cm 1 which is attributable ~L3%7~92 to an aliphatic carboxylic acid moiety bound in therubber (E/P) segment o~ the polymer. An IR o~ a sample of an identical hydrogenated diblock copolymer which was not contacted with CO2 did not show a signal at S 1715 cm 1. Also, neither of the IR's showed a signal at 1690 cm 1 which would be characteristic of a carboxylic acid moiety bound in the aromatic segment of the polymer. It can, then, be concluded that the process according to the invention incorporates the functional groups into the polyolefin portion of the polymer and not into the aromatic portion thereof.
THE PREPARATION THEREOF
The invention relates to a process for the preparation of a functionalized hydrogenated polymer.
The invention also relates to a functionalized, selectively hydrogenated copolymer.
Polymers containing ethylenic unsaturation are well known. When these polymers are prepared by the addition polymerization of a polyunsaturated ole~in, the unsaturation may be contained within the palymer backbone or pendent therefrom dependent upon the addition mechanism. For example, when l,3 butadiene is the monomer, the unsaturation will be internal when the addition is l,4 and external when the addition is l,2.
As is also known, both of these unsaturations are relatively unstable and are subject to both thermal and oxidative degradation. In a diolefin homopolymer or a random copolymer, degradation of an internaI double bond ~imply reduces the average molecular weight of the product. When such degradation occurs in a block copol~mer, however, degradation o~ an internal double ~ bond may be far more serious even to the extent of des~roying desired pol~meric properties. Degradation of an external unsaturation, on the other hand,~in all such polymers simply reduces the polymers elastomeric propertie~. It is well known to hydroyenate addition polymers containin~ both internal and pendent unsaturation to avoid such degradation. Hydxogenation o~ such polymers is known from, for example, U.5.
- 1 3~ ~9~
~ - 2 -: patent specifications Mos. 3,419,365; 3,644,58B;
4,400,478; 4,578,429 and Re. 27,145.
The incorporation of one or more functional groups into a polymer containing unsaturation to improve its properties for various uses is also well known. Methods for incorporating functional groups into such polymers are known from, for example, ~.S. patent specifications Nos. 3,135,716; 3,150,209 and ~,409,357. When tha ethylenic unsaturation in the initial polymer is completely saturated via hydrogenation, however, it has not, heretofore, been possible to incorpora~e functional groups into the polymer via these techniques. Moreover, when the starting polymer is a copolymer of a vinyl aromatic hydrocarbon and a polyolefin, and the residual unsaturation initially in the polyolefin portion of the copolymer has been : substantially completely saturated via hydrogenation, the functional yroups will be incorporated exclusively into the aromatic portion of the copolymer. Functional groups incorporated into the aromatic portion of the copolymer may not, however, be a~ reactive as those incorporated into the polyolefin portion of the copolymer. Moreover, ~unctional groups incorporat~d into the aromatic portion of a copolymer may not, in all cases, result in the same end-use properties.
: While it is, at least, theoretically possible to first incorporate one or more functional groups into a - : polymer and then to hydro~enate the functionalized polymer, attempts to do this have not been succes~ful to date primarily due to poisoning of thQ hydrogenation ; catalyst by tha functional group. Attempts to ~; ~ accomplish such hydrogenation have also been hampered by the potential for reductive hydrogenation and by : conversion of the functional group during hydrogenation.
. , ~3~70~2 As indicated hereinbefore, it is also, theoreti-cally, possible to first hydrogenate the polymer product and to then metalate the hydro~enated product to facilitate functionalization of the hydrogenated pol~mer. Metalization of a hydrogenated copolymer of a conjugated diene and a monovinylarene is known from U.S. patent specification No. 4,145,298. According to this specification, however, the metalated sites are then used to graft organic nitrogen compounds so as to produce a viscosity index improver~ To the extent that the residual unsaturation in the diolefin portion of the pol~mer is substantially completely hydrogenated, however, the metal sites will be incorporated princi-pally, if not exclusively, in the aromatic portion of the polymer. Such metalization, i.e., in the aromatic portion of the polymer generally requires the use of more metalating agent than does metalization of resi-dual unsaturation in the diolefin portion of the polymer and, generally, requires the use of one or more metalization promoters such as an amine. Moreover, hydroyer.ation followed by metalization increases the number of steps required to accomplish the end result.
In the light of the foregoing, it is clear that it has, heretofore, not been possible to produce a ~unctionalized hydrogenated copolymer of a monoalkenyl aromatic ~ydrocarbon and a polyole~in wherein the ~unctional groups are predominantly in the polyolefin portion o~ the polymer, at least not when the functional groups are two or mor~ carbon atoms removed fxom any r~sidual unsaturation. Noreover, it has not, heretofor~, been possible to producs a functionalized, hydrogenat~d polymer without accomplishing each in a diqtinctly separate step. The need, then, for a functionalized, hydrogenated copolymer of a monoalkenyl aromatlc hydrocarbon and a polyolefin wherein the ~ 1 3~ 7~J92 functional group~ are at least predominantly in the polyolefin portion of the copolymer and the need for a process wherein such a copolymer may be prepared with a reduced number of steps is believed to be readily apparent.
It is now been discovered that the foregoing and other disadvantages of the known functionalized thermo-plastic elastomeric polymers can be overcome or at least significantly reduced.
It is, therefore, an object of the present inven-tion to provide an improved functionalized thermoplastic elastomeric polymer and a process for making said improved functionalized thermoplastic elastomeric polymer. It is another object of this invention to provide such a functionalized thermoplastic elastomeric pol~mer which will exhibit the impxoved properties o~ a hydrogenated, functionalized thermoplastic elastomeric polymer. It is still another object of th~s invention to provide a procsss for preparing such an improved functionalized thermoplastic elastomeric polymer which requires a reduced number o~ steps. It is still a further object of ~his invention to provide an improved functionalized hydrog~nated thermoplastic polymer wherein the functional groups are predominantly, if not exclusively, in the elastomer portion of said polymer.
The foregoing and othex o~jects and advantages will becoms apparent from the description set forth herein--after.
Accordingly, the invention provides a process for the preparation of a functionalized hydrogenated polymer which process comprises the following ~tep~:
step a: contacting an unsaturated polymer with hydrogen in the presence of a hydro~enation cakalyst obtained by combining an alkoxide or a carboxylat~ o~ a metal of Group 8 and an .
alkyl or hydride of a metal of Group la, 2a or 3a of the Periodic Table of the ElPments;
step b: aftar the hydrogenation of step (a) is completed and before the hydrogenation catalyst is quenched or otherwise deactivated, contacting the hydrogenated polymer with a functionalizing agent; and ctep c: recovering the functionalized, hydrogenated polymer.
The invention also provides a functionalized, selectively hydrogenated copolymer which comprises monoalkenyl aromatic hydrocarbon monomer units and ; polyolefin monomer units wherein the functional groups are predominantly incorporated in the polyolefin portion of the polymer and separated from any residual unsaturation by at least three carbon atoms. Following the contacting with the functionalizing agent, the hydrogenation catalyst may be deactivated and the polymer product recovered as a crumb.
As indicated herein~efore, the present invention relates to a homopolymer or copolymer comprising a polyolefin which has been hydrogenated and functional-ized and to a process for hydrogenating and functional-izing such a polymer. As also indicated hereinbe~ore the hydro~enation and functionalization are, in effect, accomplished in a cingle step by first contacting the polymer with hydrogen in the pres~nce o~ a hydrogena-~ tion catalyst obtained by co~bining an alkoxide or ; ~ carbo~ylate of a Group 8 metal o~ the Periodic Table of the Ele~ents and a metal hydride or alkyl and than with a ~unctionalizing agent. As also indicated supra, the hydrogenated polymer will be contacted with said func-tionalizing agent be~ore the hydrogenation catalyst is quenched or otherwi~e deactivated.
., !~
,~
1327~92 In general, any polymer containing unsaturation, such as that imparted through the polymerization o~ a polyolefin, may be hydrogenated and functionalized by the process according to the present invention. Such polymers include homopolymers of polyole~ins, particu-larly conjugated diolefins and copolymers of one or more polyolefins, particularly conjugated diole~ins, and one or more other vinyl monomers which homopolymers and copolymers may be prepared via anionic polymerizà-tion with an organo alkali metal catalyst or initiator.Such polymers also include polyolefin homopolymers and copolymers prepared via polymerization in the presence o~ a ~ree radical initiator and polyolefin homopolymers and copolymers prepared via cationic initiation.
In general, the polyolefin homopolymers and co-polymers which are hydrogenated and functionalized in the process according to the present invention will ha~e a weight average molecul-ar weight within the range from about 2,000 to about 450,000. The copolymers which may be hydrogenated and functionalized may be random, block or tapered. In general, and when the copolymer contains one or more vinyl monomers dif~erent from the polyole~in, the polyolefin will comprise from about l to about 99% by weight of the polymer.
As indicated hereinbefore, unsaturated polymers which may be hydrogenatad and functionalized by the proce~s according to the present invention are ela-stomers comprising monomeric units of at least~one polyole~in, particularly a conjugated diole~in. In general, the unsaturated polymer may contain monomeric units o~ at least one polyolefin, particularly a conjugated diolefin, containing from 4 to about 12 carbon atoms such as, for example, l,3-butadiene, isoprane, pipe~ylene, methylpentyldiene, phenylbuta-diene, 3,4-dimethyl-l r 3-hexadiene and 4,5-diethyl~
3-octadiene.
Preferably, the unsaturated polymer will comprise monomeric units of at least one conjugated diene containing 4 to 8 carbon atoms per molecule. As also indicated hereinbefore, the unsaturated polymeric elastomer which may be hydrogenated and functionalized by the process according to the invention may be a copolymer of one or more of the aforementioned polyolefins and one or more other monomers. Other monomers which may be used include vinyl-aryl compounds such as styrene, various alkylstyrenes such as for example, a-methylstyrene, 1- and 2-vinylnaphthalene, 1-, 2- and 3-vinyltolu~ne and paraalkoxystyrenes in which the alkoxy group has in the range o~ from 1 to 20 carbon atoms, for example parametho~ystyrene.
As indicated hereinbefore, the unsaturated polymers which may be hydrogenated and functionalized with the process according to the present invention may be prepared via any of the ~nown techniques. These technigues include bulk, emulsion, suspension and solution polymerization. Moreover, any of the known initiators may be used. Such initiators include ~ree radicals and both anionic and cation polymPrization catalysts~ As is also known, elastomeric diolefin homopolymers and copolymers are most generally produced 25 Yia either an emulsion technigue using a free radical initiator or in solution using an anionic initiator.
Emulsion polymerization is, generally, accomplished at a temperature within the range of from about 20 to about 90 C and at a pressure within the range from about 1 to about 10 bar while solution pol~merization with an anionic initiator is generally carried out at a temperature within the range ~rom about -100 C to abouk 200 C at a pressure within the range from ahout 1 to about 50 bar.
~ 3 2 7 ~ 9 ~ 63293-2964 Unsaturated homopolymers and copolymers which may be ..
hydrogenated and functionalized by the process according to the present invention include those homopolymers and copolymers described in United States patent specifications Nos. 3,135,716;
3,150,209; 3,496,154; 3,498,960; 4,145,298 and 4,238,202.
Unsaturated polymers which may be hydrogenated and f~mctionalized by the process according to the present invention also include the block copolymers prepared in accordance with the process described in United States patent specifications Nos. 3,231,635;
3,265,765; 3,322,856; 4,391,949 and 4,444,953. Particularly useful block copolymers are those bl.ock copolymers having one of the general formulae:
BX-(A-B)y Az; AX-(B-A)y~Bz; x y z ~n [AX,~(B-A)y~Bz,~n Z wherein A represents a polymer block of an alkenyl-substituted aromatic hydrocarbon and B a polymer block of a conjugated diene; x and z are, independently, integers equal to 0 or 1 and y is a whole number from 1 to 25; x' and z' are, independently, integers ranging from 0 to the value of y; n is a whole number from 3 to 15, as determined by gas permeation chromatography (GPC) on a polystyrene scale and Z represents a residue of a coupling agent of a star-shaped block copolymer, such as a polyalkenyl coupling agent.
In general, the unsaturated polymers to be hydro-genated and functionalized by the process according to the present invention will be dissolved in a suitable solvent and then contacted with molecular hydrogen in the presence of a hydrogena-` - 1327092 tion catalyst obtained by combining a Group 8 metal carboxylate or alkoxide and a hydride or an alkyl of a metal of Group la, 2a or 3a of the Periodic Table of the Elements. The Periodic Table of the Elements is that shown on the inside of the cover of "~andbook of Chemistry and Physics", 61st edition (1980-1981), CRC Press Inc. Hydrogenation catalysts of this type are described in, for example, United States patent specifications Nos.
3,541,G64; 3,595,942 and 4,028,485. Of the Group 8 metals, those of the so-called Iron Group; viz. iron, cobalt and nickel are particularly effective. Of the Group la, 2a and 3a metals, lithium, magnesium and aluminum are particularly effective. A key to selecting a metal of Groups la, 2a and 3a for use in the hydrogenation catalyst is, of course, the stability of the metal alkyl formed by reaction of the initial hydride or alkyl with the polymer. In this regard, it has been ~ound that the aluminum polymer alkyl is the least stable of those formed with the metals tested. It is, then, important that the subsequent contacting with a functionalizing agent be accomplished relatively quickly after hydrogenation when a catalyst comprising aluminum is used.
The lithium polymer alkyl on the other hand is very stable. As a result, contacting with the functiona]izing agent after hydrogena-tion may be delayed for relatively long periods.
In general, the hydrogenation will be accomplished in a suitable solvent at a temperature within the range from about 20 C to 150 C at a hydrogen partial pressure below 70 bar and contacting between the polymer and the hydrogen will be maintained _ g _ n~
~ 3 2 7 0 9 ~ 63293-296~
for a nominal holding time within the range from about 10 to about 1000 minutes. Suitable solvents for use during the hydrogenation inclu~e, but are not limited to, hydrocarbons such as paraffins, cycloparaffins, : - 9a -n ~:i i327~92 alkyl-substituted cyclopara~fins, aromatics and alkyl-substituted aromatics containing ~rom about 4 to about lO carbon atoms per molecule. Suitable solvents include for example, benzene, toluene, cyclohexane, methylcyclohexane, n-butane, n-hexane and n-heptane.
While the applicant does not wish to be bound by any particular theory, it is believed khat both the Group 8 metal and the metal selected from Groups la, 2a and 3a will react with the ethylenic unsaturation contained in the polymer to form polymeric alkyls during the hydrogenation. The ~roup 8 metal polymer alkyls are, however, relatively unstable and do not become involved in the subsequent functionalization reaction. The Group la, 2a and 3a metal polymer alkyls are, however, significantly more stable and the metal site, if not removed or otherwise rendered inactive durlng hydrogenation, will be availab~e for subsequent reaction with the functionalizing agent. In any case, the functional group ultimately will be bonded to a carbon atom which initially was bonded to another carbon atom through a double bond. As a result, the functional group will be separated from any residual unsaturation by at least three carbon atoms. While still not wishing to be bound by any particular theory, it is also believed that the amount of functionalizing agent that may be incorporated is, in effect, propor-tional to the number of ~roup la, 2a and 3a metal atoms actually contained in the hydrogenation solution; or at least incorporated into the polymer during hydxogena-tion. The amount of ~unctionalizing agent ultimatelyin~-orporat~d can, then, be controlled by controlling the amount of Group la, 2a and 3a metal added as a catalyst component and by controlling the extent of hydrogenation at least to the point that the ethylenic unsaturation is not completely hydrogenated. In any case, polyolefin portion of the polymer may be substantially completely saturated, if desired, partly due to hydrogenation and partly due to reaction with the functionalizing agent.
In general, the hydrogenation will be a~complished such that from about lO to about 99% of the initial unsaturation in the polyolefin portion of the polymer becomes saturated during hydrogenation. At least a portion of the remaining unsaturation may, then, contain a metal atom which will be available for subsequent reaction with the selected functionalizing agent.
As indicated hereinbefore, the hydrogenated or partially hydrogenated polymer is next functionalized by contacting the same with a suitable functionalizing agent after the hydrogenation step has been completed or at least staxted and before the hydrogenation catalyst is quenched or otherwise deactivated.
Functionalizing agents which will react with the partially hydrogenated polymer include, but are not necessarily limited to for example, carbon dioxide, ethylene oxide, aldehydes, ketones, carboxylic acids, carboxylic acid salts, carboxylic acid esters, halides, epoxides, sulphur, boron alkoxides, isocyanates and various silicon compounds. In general, contacting of the hydrogenated polymar and the functionalizing agent will be accomplished at a temperature within the range o~ from 20 C to 150 C and at ~ nominal holding time within the range from about l to about 200 minutes.
Once the functional group ~r groups have been incorporated, the polymer may be recovered and then used in any o~ those applications for which the polymer is known to be u~eful. Alternatively, and where the functional group was incorporated for the purpose of enabling grafting or other reaction, the grafting or other reaction could bs compl2ted.
12 ~ 3 2 70 g2 In general, from about O.l to about 5% of the ; initial unsaturation in the polyolefin portion of the polymer will become saturated as a result o~ reaction with a ~unctionalizing agent, thereby incorporating from about O.Ol to about 5 wt~ functional groups, based on final product. Moreover, the functionalization (hydrogenation) operating conditions actually contemplated for use ln the process according to the invention have been selected so as to insure that a predominant amount (more than 50%) of the . functionalizing agent is incorporated into the ; polyolefin portion of the polymer. Further, these operating conditions can be even more restricted, as in the preferred embodiment, to insure that substantially all of the functionalizing ag~nt is incorporated into the polyole~in portion of the polymer. As used herein, the recitation "substantially all" is intended to mean that at least 95% o~ the functionalizing agent i5 incorporated into the polyole~in portion of the polymer.
In a preferred embodiment of the present : invention, an unsaturated block copolymer comprising at le~st one diolefin block and at least one of a vinyl--substituted aromatic hydrocarbon block will be selectively hydrogenated and then cantacted with carbon dioxide to incorporate functional groups. The block copolymer will be prepared using the method described in U.S. patent specification No. 3,231,635. In a most pr~erred embodiment o~ the present invention, the block copolymer will comprise three blocks and may be : represented by the ~eneral formula A-B-A wherein A and B are, respectively, polymer blocks of an alkenyl-sub-stituted aromatic hydrocarbon and a diolefin. In both ~he prefarred and most pre~erred embodiments, the alkenyl-substituted aromatic hydrocarbon blocks will ~L327~2 have a weight average molecular weight within the range from about 2,000 to about 50,000 and the diolefin blocks will have a number average molecular weight within the range from about 2,000 to about 150,000. In the most preferred embodiment of the present invention, the alkenyl-substituted aromatic hydrocarbon will be styrene and the diole~in will ~e a conjugated diolefin, particularly either butadiene or isoprene.
In both the preferred and most preferred ~mbodi-ments, the block copolymer will be hydrogenated justafter its production in solution with an anionic ini-tiator, particularly a butyllithium compound. The hydrogenation will be completed in the presence of a hydrogenation cataly~t prepared by combining nickel octoate and sec-butyllithium. The molar ratio of nickel to lithium in the catalyst will be within the range from about 0.1:1 to about 0.6:1. The catalyst will be used at a concentration sufficient to provide from about 50 to about 500 parts per million (ppm), by weight, o~ nickel in the polymer cement.
In the preferred and most preferred embodiment , the hydrogenation will be accomplished with a hydrogen partial pres~ure in the rang of from 7.9 to 56.2 bar and at a temperature within the range from 40 to 80 C.
Contacting between the polymer and the hydrogen will be maintained for a pariod of time within the range from about 60 to about 240 minutes. In the pre~srred and most preferred embodiment from about 80 to about 98% of the initial unsaturation in the diole~in polymer will be saturated with hydrogen during hydrogenation.
A~ter the hydrogenation reaction has been completed but before the reaction is quenched or the catalyst otherwisa deactivated, and in a preferred embodimant, the polymer will be contacked with C02 at a C2 partial pressure within the range fxom about 1.7 to `` ~ 327~92 ~ - 14 -about 35.5 bar and at a temperature within the range from about 20 to about 80 C, preferably 40 C to 80 C. Contacting o~ the polymer with C02 will be continued ~or a period of time within the range ~rom about 1 to about 120 minutes. The contacting of the polymer and C02 will be accomplished in the presence of the same catalyst as was used during the hydrogenation.
In both the preferred and most pre~erred embodiments from about 0.~ to about 2.0~ of the initial unsatura-tion contained in the diolefin portion of the copolymer will be saturated as a result of reaction with the functionalizing agent.
After contacting of the polymer with carbon dioxide is completed, the hydrogenation and functionalization reaction~ may be quenched or the catalyst otherwise deactivated using known techniques.
Reaction with an aquPous sulphuric acid solution is, however, particularly preferred following contacting with carbon dioxide since this will convert the metal salt group to the carboxyl group. Following quenching or deactivation of the hydrogenation catalyst, the polymer may be separated and recovered as a crumb and then used in any of the applications ~or which a carboxylated pol~m~r would be useful. The polymers produc~d in the preferred and most preferred embodiment are particularly us~ul a~ a modifier in sheet moulding and bulk moulding compo~itions.
The following Examples ~urther illustrate the invention.
ExamE~
In this example, 88 g o~ a styrene-butadiene diblock copolymer were hydrogenated and then contacted with carbon dioxide (C02) in the prasence of a catalyst con~isting o~ the raaction product of nicXel octoate and sec-butyllithium, whic~ had been combin~d in a ~327~92 Ni:hi molar ratio o~ 1:6. In the diblock polymer, khe styrene blocks had a molecular weight of 37,000 and the butadiene blocks had a molecular weight of 63,000. The hydroganation was started at a temperature o~ 40 C and with a hydrogen partial pressure of 45.8 bar. The hydro-genation was completed in the presence of su~icient catalyst to provide 70 ppm. by weight of nickel based on block copolymer solution. The catalyst was added in 3 increments. A*ter each increment was added, an exotherm was noted. After the first increment was added, the hydrogenation temperature rose to 52 C, after the second increment was added the hydro~enation temperature ro~e to 65 C and a~ter the third increment was added thP hydrogenation t~mperature rose to 74 C.
The hydrogenation was then continued for about 180 minutes then at a temperature of 80 C. After complekion o~ the hydrogenation, $7.5 per cent of th~
olefinic unsaturation had been hydrogenated. The extent of hydrogenation was determined using an ozone titration technique. The hydrogenated diblock wa~
metalated. Without further treatment, the freshly hydrogen~ted, metalated block copolymer was functionalized by reaction with an excess of C02.
Following the ~2 contacting, 1% by weight (wt) H2S04 in water was added to the mixture to deactivate and separate the hydrogenation catalyst. Following this deactivation and separation, the polymer was recovered as a crumb using an excess of isopropyl alcohol.
To demonstrate ~hat the recovered product was a carboxylate polymer, solution viscosity expariments were per~ormed which showed that the polymer was iono-meric. Spe~ifically, a 6 wt~ solution o~ the product polymer in cyclohexane was separated into 3 aliquots o~
25 g each. The first, hereinafter solution 1, was a control and was not alter~d; the second was treated 13~7~
with 1 ml of acetic acid to minimize ionic association arising from polymer bound-CO~- moieties; and the third was treated with 5 g Mg(OH~2, to maximize the ionic association o~ the polymer -C02- sites. The three solutions were allowed to equilibrate for 2 days before the viscosity measurements were made using a Brook~ield Viscometer. The measured viscosities of solutions 1, 2 and 3 were 68, 55 and 72 cP, respectively. As expected, the solution with the maximum ionic interaction, solution 3, was more than 30% more viscous than the solution wherein ionic interaction had been minimized, i.e., solution 2.
For purposes of comparison, the viscosity of 6 wt%
solution o~ an identical hydrogenated diblock copolymer which had not been contacted with a functionalizing agent was 18 cP. Treatment of this solution with both acetic acid and Mg(OH)2 gav~ solutions having viscosi-ties of 16 cP a~ter 2 days.
Example 2 In this example, the procedure of Example l was repeated exc2pt that the hydrogenation temperature and holding time were reduced so as to produce a diblock copolymer having only 23~ of the olefinic unsaturatio~
hydrogenated. A 1200 g aliquot of the resulting polymer cement was then combined with 8.4 g o~ a ~unctionaliza-tion promoter; viz., N,N,N',N'-tetramethylethylenedi-amine and then contacted with C02 in the same manner as described in Example 1. An aliquot af the reco~ered carbo~ylated polymer was then dissolved in tatrahydro- -furan and titrat~d with standardized methanolic XOH to a phenolphthalein endpoint. This titration revealed 0.02 wt% polymer bound carboxylic acid; i.e., pendent -C02H groups.
An infrared (IR) spectrum of the carboxylated polymer had a signal at 1715 cm 1 which is attributable ~L3%7~92 to an aliphatic carboxylic acid moiety bound in therubber (E/P) segment o~ the polymer. An IR o~ a sample of an identical hydrogenated diblock copolymer which was not contacted with CO2 did not show a signal at S 1715 cm 1. Also, neither of the IR's showed a signal at 1690 cm 1 which would be characteristic of a carboxylic acid moiety bound in the aromatic segment of the polymer. It can, then, be concluded that the process according to the invention incorporates the functional groups into the polyolefin portion of the polymer and not into the aromatic portion thereof.
Claims (22)
1. A process for the preparation of a functionalized hydrogenated polymer which process comprises the following steps:-step a: contacting an unsaturated polymer with hydrogen in the presence of a hydrogenation catalyst obtained by combining an alkoxide or a carboxylate of a metal of Group 8 and an alkyl or hydride of a metal of Group 1a; 2a or 3a of the Periodic Table of the Elements;
step b: after the hydrogenation of step (a) is completed and before the hydrogenation catalyst is quenched or otherwise deactivated, contacting the hydrogenated polymer with a functional-izing agent; and step c: recovering the functionalized, hydrogenated polymer.
step b: after the hydrogenation of step (a) is completed and before the hydrogenation catalyst is quenched or otherwise deactivated, contacting the hydrogenated polymer with a functional-izing agent; and step c: recovering the functionalized, hydrogenated polymer.
2. A process as claimed in claim 1 in which said hydro-genation is accomplished at a hydrogen partial pressure below 70 bar and at a temperature in the range of from 20 °C to 150 °C.
3. A process as claimed in claim 1 in which the hydrogena-ted polymer from step (a) is contacted with the functionalizing agent at a temperature in the range of from 20 °C to 150 °C.
4. A process as claimed in claim 1, 2 or 3 in which said functionalizing agent is a carboxylic acid or a salt of a car-boxylic acid.
5. A process as claimed in claim 1, 2 or 3 in which said functionalizing agent is a silicon compound.
6. A process as claimed in claim 1, 2 or 3, in which said functionalizing agent is carbon dioxide.
7. A process as claimed in claim 1, 2 or 3 in which said Group 8 metal is an iron group metal.
8. A process as claimed in claim 7 in which said Group 8 metal is nickel.
9. A process as claimed in claim 1, 2, 3 or 8 in which said metal from Groups 1a, 2a or 3a is lithium, magnesium or aluminum.
10. A process as claimed in claim 9 in which said lithium is introduced as a lithiumalkyl.
11. A process as claimed in claim 10 in which said lithiumalkyl is sec-butyllithium.
12. A process as claimed in claim 1, 2, 3, 8, 10 or 11 in which the hydrogenation catalyst is deactivated after the con-tacting with the functionalizing agent is complete.
13. A process as claimed in claim 1, 2, 3, 8, 10 or 11 in which said hydrogenation catalyst is deactivated by contacting with an acid.
14. A process as claimed in claim 13 in which the de-activation takes place by contacting with an aqueous solution containing sulphuric acid.
15. A process as claimed in claim 1, 2, 3, 8, 10, 11 or 14 in which the unsaturated polymer is a block copolymer having one of the general formulae:
Bx-(A-B)y-Az; Ax-(B-A)y-Bz; [Bx'-(A-B)y-Az']n-Z and [Ax'-(B-A)y-Bz']n-Z wherein A represents a polymer block of an alkenyl-substituted aromatic hydrocarbon and B a polymer block of a conjugated diene; x and z are, independently, integers equal to 0 or 1 and y is a whole number from 1 to 25; x' and z' are, independently, integers ranging from 0 to the value of y; n is a whole number from 3 to 15, as determined by - 19a -gas permeation chromatography on a polystyrene scale and Z represents a residue of a coupling agent of a star-shaped block copolymer.
Bx-(A-B)y-Az; Ax-(B-A)y-Bz; [Bx'-(A-B)y-Az']n-Z and [Ax'-(B-A)y-Bz']n-Z wherein A represents a polymer block of an alkenyl-substituted aromatic hydrocarbon and B a polymer block of a conjugated diene; x and z are, independently, integers equal to 0 or 1 and y is a whole number from 1 to 25; x' and z' are, independently, integers ranging from 0 to the value of y; n is a whole number from 3 to 15, as determined by - 19a -gas permeation chromatography on a polystyrene scale and Z represents a residue of a coupling agent of a star-shaped block copolymer.
16. A process as claimed in claim 15 in which the alkenyl-substituted aromatic hydrocarbon is styrene and the conjugated diene is 1,3-butadiene or isoprene.
17. A functionalized, selectively hydrogenated copolymer which comprises monoalkenyl aromatic hydrocarbon monomer units and polyolefin monomer units wherein the functional groups are predominantly incorporated in the polyolefin portion of the polymer and separated from any residual unsaturation by at least three carbon atoms.
18. A copolymer as claimed in claim 17 in which said monomer units are incorporated as blocks and wherein the monoalkenyl-aromatic hydrocarbon blocks have a weight average molecular weight in the range of from 2,000 to 50,000 and the polyolefin blocks have a weight average molecular weight in the range of from 2,000 to 150,000.
19. A copolymer as claimed in claim 18 in which said functional groups are substantially all incorporated into the polyolefin blocks.
20. A copolymer as claimed in claim 19 in which said functional group is a carboxyl group or a carboxylic acid salt group.
21. A copolymer as claimed in claim 19 in which said functional group contains silicon.
22. A copolymer as claimed in claim 19 in which from 10 to 99% of the initial unsaturation in the polyolefin portion of said copolymer is hydrogenated and in which from 0.1 to 5% of said initial unsaturation is consumed as the result of reaction with a functionalizing agent.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/077,827 US4851476A (en) | 1987-07-27 | 1987-07-27 | Functionalized polymers and process for modifying unsaturated polymers |
| US77,827 | 1993-06-15 |
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| CA1327092C true CA1327092C (en) | 1994-02-15 |
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| CA000573024A Expired - Fee Related CA1327092C (en) | 1987-07-27 | 1988-07-26 | Functionalized polymers and process for the preparation thereof |
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| US (1) | US4851476A (en) |
| EP (1) | EP0301665B1 (en) |
| JP (1) | JPS6443518A (en) |
| AU (1) | AU605338B2 (en) |
| BR (1) | BR8803697A (en) |
| CA (1) | CA1327092C (en) |
| DE (1) | DE3882098T2 (en) |
| ES (1) | ES2056901T3 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5107051A (en) * | 1989-03-14 | 1992-04-21 | Exxon Chemical Patents Inc. | Halogen resistant hydrotreating process and catalyst |
| US4966946A (en) * | 1990-02-02 | 1990-10-30 | Great Lakes Chemical Corporation | Block copolymer of polyalkylene and halogenated polystyrene |
| EP0476737A3 (en) * | 1990-08-27 | 1992-05-06 | Shell Internationale Research Maatschappij B.V. | Block copolymer of polyalkylene and halogenated poly(vinyl aromatic) |
| US5334441A (en) * | 1992-01-30 | 1994-08-02 | Gencorp Inc. | Composite comprising unsaturated polyester-flexible polymer block copolymer coated fiber structures in a polyester or vinyl ester resin matrix |
| US5362819A (en) * | 1992-01-30 | 1994-11-08 | Gencorp Inc. | Polyester-flexible polymer block copolymers and mixtures thereof |
| US5428068A (en) * | 1992-01-30 | 1995-06-27 | Gencorp Inc. | Unsaturated polyester-modified flexible polymers for use in molding composition |
| US5385963A (en) * | 1992-01-30 | 1995-01-31 | Gencorp Inc. | Unsaturated polyester-modified flexible copolymers for use in sheet molding compositions |
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| US5342554A (en) * | 1993-01-07 | 1994-08-30 | Gencorp Inc. | Vinyl-terminated polyesters and polycarbonates for flexibilizing and improving the toughness of compositions from unsaturated polyesters and fiber reinforced plastics made from them |
| US5376721A (en) * | 1993-01-29 | 1994-12-27 | Gencorp Inc. | Low-profile additives for thermosetting polyester compositions |
| US5565092A (en) * | 1994-03-16 | 1996-10-15 | Exxon Chemical Patents Inc. | Halogen resistant hydrogenation process and catalyst |
| US6242537B1 (en) * | 1998-03-30 | 2001-06-05 | Shell Oil Company | Gel-free process for making hydrogenated functionalized anionically polymerized polymers |
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| US6867264B2 (en) | 2002-08-28 | 2005-03-15 | Kraton Polymers U.S. Llc | Process for removing residual silicon species from hydrocarbon solvents |
| TW201917018A (en) * | 2017-10-25 | 2019-05-01 | 美商陶氏全球科技有限責任公司 | Tile containing primer coated substrates with good adhesion |
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| US27145A (en) * | 1860-02-14 | Mortising-machine | ||
| US3135716A (en) * | 1958-11-06 | 1964-06-02 | Phillips Petroleum Co | Process for preparing terminally reactive polymers |
| US3150209A (en) * | 1961-05-15 | 1964-09-22 | Phillips Petroleum Co | Compositions from terminally reactive polymers |
| NL288289A (en) * | 1962-01-29 | |||
| US3231635A (en) * | 1963-10-07 | 1966-01-25 | Shell Oil Co | Process for the preparation of block copolymers |
| US3322856A (en) * | 1963-11-07 | 1967-05-30 | Shell Oil Co | Method of preparaing diene elastomer/block copolymer composition |
| US3496154A (en) * | 1965-10-15 | 1970-02-17 | Phillips Petroleum Co | Random copolymerization |
| NL133183C (en) * | 1966-11-21 | |||
| US3498960A (en) * | 1967-09-28 | 1970-03-03 | Phillips Petroleum Co | Production of random copolymers in organolithium polymerization systems |
| US3541064A (en) * | 1968-07-11 | 1970-11-17 | Bridgestone Tire Co Ltd | Hydrogenation catalysts and a process for hydrogenating polymers by the use of them |
| US3595942A (en) * | 1968-12-24 | 1971-07-27 | Shell Oil Co | Partially hydrogenated block copolymers |
| BE756177A (en) * | 1969-09-17 | 1971-03-15 | Shell Int Research | PROCESS FOR PREPARING HYDROGENATED BLOCK COPOLYMERS |
| US4028485A (en) * | 1976-01-29 | 1977-06-07 | Mobil Oil Corporation | Non-aqueous removal of soluble hydrogenation catalyst |
| US4145298A (en) * | 1977-08-22 | 1979-03-20 | Phillips Petroleum Company | Hydrogenated lithiated copolymers grafted with organic nitrogen compounds as viscosity index improvers having dispersant properties |
| US4238202A (en) * | 1979-08-31 | 1980-12-09 | Phillips Petroleum Company | Hydrocarbon fuels with carburetor detergent properties |
| DE3044355A1 (en) * | 1979-11-30 | 1981-08-27 | Kanegafuchi Kagaku Kogyo K.K., Osaka | VINYL CHLORIDE COPOLYMER AND ITS COMPOSITION |
| US4409357A (en) * | 1981-09-10 | 1983-10-11 | Atlantic Richfield Company | Footwear-compounds from derivatized star-block copolymers |
| US4391949A (en) * | 1981-11-12 | 1983-07-05 | Shell Oil Company | Asymmetric block copolymers and corresponding adhesive formulations |
| US4444953A (en) * | 1981-11-12 | 1984-04-24 | Shell Oil Company | Assymetric block copolymers and corresponding adhesive formulations |
| US4400478A (en) * | 1982-12-23 | 1983-08-23 | Shell Oil Company | Molding compounds comprising a mixture of block copolymers employed as a modifier for thermosetting unsaturated polyester resin compositions |
| US4578429A (en) * | 1984-08-31 | 1986-03-25 | Shell Oil Company | Selectively hydrogenated block copolymers modified with acid compounds or derivatives |
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1987
- 1987-07-27 US US07/077,827 patent/US4851476A/en not_active Expired - Fee Related
-
1988
- 1988-07-25 JP JP63185340A patent/JPS6443518A/en active Pending
- 1988-07-25 BR BR8803697A patent/BR8803697A/en not_active IP Right Cessation
- 1988-07-25 AU AU20000/88A patent/AU605338B2/en not_active Ceased
- 1988-07-26 EP EP88201618A patent/EP0301665B1/en not_active Expired - Lifetime
- 1988-07-26 DE DE88201618T patent/DE3882098T2/en not_active Expired - Fee Related
- 1988-07-26 ES ES88201618T patent/ES2056901T3/en not_active Expired - Lifetime
- 1988-07-26 CA CA000573024A patent/CA1327092C/en not_active Expired - Fee Related
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|---|---|
| ES2056901T3 (en) | 1994-10-16 |
| EP0301665A2 (en) | 1989-02-01 |
| AU2000088A (en) | 1989-01-27 |
| DE3882098T2 (en) | 1993-10-21 |
| US4851476A (en) | 1989-07-25 |
| BR8803697A (en) | 1989-02-14 |
| JPS6443518A (en) | 1989-02-15 |
| EP0301665A3 (en) | 1990-01-31 |
| AU605338B2 (en) | 1991-01-10 |
| DE3882098D1 (en) | 1993-08-05 |
| EP0301665B1 (en) | 1993-06-30 |
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