CA2088782A1 - Polymerization of selected vinyl monomers - Google Patents

Abstract

A process for the polymerization of selected acrylic and maleimide monomers by contacting the monomers with a diazotate, cyanate or hyponitrite, and N-chlorosuccinimide, N-bromosuccinimide or a diazonium salt. The polymers produced can themselves initiate further polymerization. Block copolymers can be produced.

Description

2 PCT/US9ttO5331 Pol~ization of vinyl monomers with a new catalytic system EI~D OF TNVE~TTQ~
SThis invention concerns a process for the polymerization of selected vinyl monomers, by contacting the vinyl monomer wlth an aryl diazotate, a cyanate, or a hyponitrite, and an aryl diazonium shlt or an N-halosuccinimide. The polvmers produced are useful for initiating further polymerizatlon. Useful block polymers can also be produced.
~ GROUND ~F ~F INVENTION
H. K. Hall Jr. and M. A. Howey, Polym. Bull., vol.
12, pg. 427-431 ~1984) report that ~ryl diazonium salts polymerize p-methoxystyrene in nitrobenzene. No mention is made of cyanates or hyponltrites, or the ability to restart the polymerization.
H. Warson in two papers ~Die Makromol. Chem., vol.
105, pg. 22~-250 ~1967)) reports that aryl diazonium compounds with either bisulfite or hypophosphorous acid will polymerize acrylonitrile.
P. R. Singh, et al., Tet. Lett., vol. 23, pg. 5191-~, S194 (1982) report the aryl diazonium ions react with nitrite ions to give free radical type intermediates.
No mention is made of polymerization.
C. Walling, Free ~adlcal in Solutlon, John Wiley &Sons, Inc., New York, 1957, pp. 510-519 and W. E.
Bachmann and R. A. Hoffman, in R. Adams, Ed., Organic Reactions, Vol. II, John Wiley L Sons, Inc., New York, 1944, pp. 226-230 speculate that aryldiazohydroxides, which are said to be in equilibrium with their sodium salts when in contact with sodium hydroxide, decompose readily at room temperature to give free radicals.
In all of the above references, there is no mention of the use of diazotate, cyanate, hyponitrite -. '~' , 208~82 "coagentsn, the use of these compounds for acrylic polymerizations, or the possibility of an "interruptible" polymerization.
U.S. Patent 4,SBl,429, descrlbes the use of a S compound of t~e Sormula (~ere modlf~ed~ R~2N-O-X, wherein R~ is a hindered alkyl group and X ls a group contalning at least one carbon atom. Although thls compound can inltiate acryllc polymerlzation, and the polymerizatlon ~s lnterruptible, no mention $s made of diazonium salts, diazotates, eyanatcs or hyponltrites.
V.S. Patent 4,761,360 descrlbes a llght sensltlve materlal contalning a silver hallde, a reduclng agent, a ; polymerizable compound ~vinyl monomer) and a silver diazotate. This mixture is reported to be stable ~indeed it is said to be an advantage) until the material is exposed to light, and then heated, at which time the vinyl monomer is polymerized. In the lnstant , process a silver halide is not present.
It is the object of this inventlon to provide a method for the polymerization of acryllc and maleimide monomers, by contacting the monomers wlth an aryl diazotate, a cyanate, or a byponitrite, and an aryl diazonium salt or an N-halosuccinimlde. This process, whlch may be carried out ln a varlety of ways, such as neat, in solution, or as an emulsion, may be restarted after the polymerization has stopped. This surprislng " ..
property may be utillzed to prepare block copolymers.
RY OF TP~ TN~JENT10~
This invention concerns a process for the polymerization of vinyl monomers, comprislng, contacting: ;
~a) an acrylic monomer or N-phenylmalelmide;
(b) a diazotate of the formu.a Arl-N-N-O- M~, or a ` cyanate of the formula MOCN, or a hyponitrite of the W092tO2561 2 0 8 ~ ~ 8 2PCT/~S9l/05331 formula M2N202, wherein Ar1 is aryl or substituted aryl, and M is a metal or a tetrahydrocarbylammonium ion; and (c) N-chlorosuccinimide, N-bromosuccinimide, or a - diazonium salt of the formula Ar2N2~ X~, wherein Ar2 ls aryl or substituted aryl, and X is an anion.
~=~
Among the vinyl monomers uscful ln the lnstant process are acrylic monomers, partlcularly acryllc acids and esters. By the term acrylic 1Q meant a compound of the formula ~' R3 ' `.:, CH2-C-C-15' O

where~n the open valence is attached to a hydrocarbyloxy or substituted hydrocarbyloxy group to form an ester, or a hydroxy group to form an acid. The group R3 $s an ''~ alkyl group containlng up to 4 carbon atoms or hydrogen.
Preferred R3 groups are methyl and hydrogen. Preferred acrylic monomers are acryllc acid, methacryllc acid, ; methyl acrylate, ethyl acrylate, butyl acrylate, methyl : 2S methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, phenyl acryl~te~ cyclohexyl metbacrylate, 2-hydroxyethyl acrylate, and 2-hydroxyethyl methacrylate.
By the term ~substituted hydrocarbyl(oxy)~ herein is meant a hydrocarbyl(oxy) group that contalns one or ' more substituents that do not interfere with the polymerization process. The substituents may be between hydrocarbyl segments, such as ether ~nd amino. Examples of other suitable substituents'lnclude,' but are not limited to fluoro, keto (oxo), ester, amido, and silyl.
The cyanates, diazotates, and hyponitrl'tes used herein are metal and tetrahydrocarbylammonium salts. ~y ;

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' WO92/02561 PCT/US91tO5331 20~782 4 `

the term "substituted" aryl herein is meant an aryl group that contains one or more substituents that do not interfere with the polymerization process. The substituents may be between hydrocarbyl ~egments, such . S as ether and ~mino. Examples of other su~table substltuents include, but are not llmlted to fluoro, keto (oxo), ester, amide, silyl, alkyl, and cycloalkyl.
It is preferred if the aryl group, Arl, ls substituted w$th one or more electron withdrawlng substltuents. An - 10 elcctron wlthdrawlng substltuent has a ~o-called H~mmett Constant of about 0.2 or more ~for a llsting of Hammett Constants, see H. Jaffe, Chem. Rev., vol. 53, pg. 222-223 ~1953), which is hereby lncluded by reference).
Especially preferred substltuents are nltro and nitrile.
Especially preferred Arl groups are p-nitrophenyl, and p-cyanophenyl. Preferred metal lons for the cyanate, diazotate, and hyponitrite salts are alkali metals and i tetraalkylammonium and especially preferred are sodium, po~assium and tetraalkylammonium.
The diazonium salts used in the lnstant proccss j have the formula Ar2N2+ X~, and such diazonium compounds are well known to those skilled ln the art. It ls preferred if the group Ar2 ls derived from benzene, and preferred Ar2 groups are phenyl, ~nd p-nitrophenyl.
Preferred anions X are chlorlde, hexafluorophosphate, hexafluoroantimonate, and tetrafluoroborate.
The process may be run neat ~no addltional compounds added) or ln a solvent, emulsion or ~uspension. No matter how the reaction ~s run, lt ls ~` 30 important that at least some of each ingredient be present in a single phase, at least to start the ~-` polymerization. For example, when the process is run ~- neat, ingredients (b) and ~c), which are salts, may not be soluble in the neat reaction medium, which~normally - ;
is mostly vlnyl monomer. Thus the salts may be .-:
- ' , - ' . '.

WO92/02561 PCT/US9t/05331 2~8~782 solublized by the addition of small amounts of polar solvents, or so-called crown ethers, which are known to those skilled in the art to solublize ionic compounds in nonpolar solvents. Other well known methods may be used. By a solvent ls usually meant a compound t~at can dissolve the monomer, polymer, and at least a ~mall amount of the ~b) and (c) components, although, for example, the solvent m~y only dissolve small amounts of polymer. Small amounts of compatibillzlng compounds, such as methanol, acetone And tetrahydrofuran, may also be useful. The process may be run ln emulsion or suspension, preferably aqueous emulsion and agueous suspension. These various methods are illustrated in the examples.
The process is run at from about -20C to about ; 120C, preferably about 0C to about 60C, and most preferably about 10C to about 40C. During rapid polymerization, cooling may be necessary to control the temperature. It is preferred to exclude oxygen, a convenient method to do this is to use An inert atmosphere such as nitrogen. The use of mild agitation is preferred, especlally lf the lngredients and/or products form more than one phase.
It is possible with this process to prcpare block copolymers. By block copolymer i5 meant ~... a polymer comprising molecules in which there is a linear arrangement of blocks. A block is deflned as a portion of a polymer molecule in w~ich the monomerlc units have at least one constitutional or confi~urational feature absent from adjacent portions. In a block copolymer the distinguishing feature is constitutional, i.e., each of the blocks comprises units derived from a characteristic species of monomer.~ (Quotation from H. Mark, et. al., Encyclopedia of Polymer Science hnd Engineering, John Wiley and Sons, New York, 1985, vol. 2, pg. 324.) Block .
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W092/0256l 2 0 8 ~ 7 ~ 2 PCT/US91/05331 copolymers are produced by sequential addition of monomers. That is, a block is started with one or more monomers. When those monomers are used up (polymerized), a second monomer(s) is added to make the next block. Block polymers ~re a preferred product of this process.
The polymers made by the process of thls lnvention, even after isolation, as by strlpplng off solvent under vacuum, or precipitation from a nonsolvent, retain the unusual property of belng able to lnltlate polymerization (herein termed a ~secondary polymerizationn) of one of the selected monomers useful in the instant process. Temperatures needed for this secondary polymerization are about B0C to about 120C, preferably about 90C to about 100C. For the secondary polymerization no other ingredients other than the vinyl monomer and polymer are necessary, but lt is convenlent to mix the vinyl monomer and polymer in solution, so it is preferred to carry out the secondary polymerization in a solvent. If the polymer is soluble in the vinyl monomer, the monomer may act as the solvent, in other words, in this case the secondary polymerization ls done neat. Block copolymers may also be made by secondary polymerization. It is preferred if oxygen is excluded from the secondary polymerization.
The polymers produced by the instant process are useful as molding reslns, in coatings, And in films.
They may be formed into useful articles by processes well known to those skilled in the art.
In the Examples that follow, the following Abbreviations are used:
BA - n-butyl acrylate E~MA - 2-ethylhexyl methacryl_te HEMA - 2-hydroxyethyl methacrylate MA - methyl acrylate - W092/02561 2 0 8 ~ 7 ~ 2 PCT/US91/05331 MAA - methacrylic acid - MMA - methyl methacrylate Mn - number average molecular weight Mw - weight average molecular weight -~- 5 P - indicates the polymer of the monomer acronym - that follows Ph or - phenyl or phenylene THF - tetrahydrofuran ~per~mental Procedu-e for Ex~mpleg 1-26 ~ab1e ) ~I~L
To a 6 cc glass vial, containlng a Teflon~-coated stir bar, in a N2-filled dry box, was charged: O.l m mole 0N2BF4, 0.5 cc N2-purged acetone, and 9.4 m mole N2-purged MMA. Then 0.05 mmole Na2N202 was added, the vlal was sealed with a Teflon~-coated silicon dis~, and stirring was started. After stirring for 24 hours, the ; contents of the vial were combined with 5 cc.CH2Cl2 which was then poured lnto 20 cc of 0 methanol. The precipitated polymer was air drled and a sam2le was analyzed by GPC, giving MW - 32,400 and MN ~ 16,400.
Examples l through 26 were All carried out essentially identically, except for minor dlfferences noted at the bottom of Table I. Most reactions lnvolved ~5 syringe needle sparging wlth N2 to remove air. The finallPolymers were analyzed by GPC on total product samples obtained by slmply removlng volatlles by vacuum (0.1 mm Hg), except for Examples l and 4, whlch lnvolved preclpltating the polymers from CH2Cl2 w~th methanol.

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WO92/02561 PCT/US9l/05331 208~782 12 =~
To a 50 cc three-necked glass round-bottomed flask, equipped with a thermometer, Teflon~-coated stir bar, water-cooled condenser, and N2 lnlet and outlet tubes, was charged: 1.98 mmoles 0N2BF4, 0.78 mmoles Na2N22~
and 214 mmoles MMA. The mlxture was stlrred and purged with N2 using a needle to admit N2 through the liquld for te~ minutes. The needle was then changed to the vapor space. At t-0, 10 cc of N2-purged methanol was in~ected, the pot was heated by means of an electrlc heating mantle to a liquid temperature of 40C, and samples of about 1.5 cc each were w~thdrawn by syringe at the times shown below. Each sample was weighed in a 25 cc filter flask, vacuum stripped to remove volatiles (0.1 mm Hg) and re-weighed. GPC analyses were done for . Mw and Mn~ and % conversion was calculated for each sample.

Reaction t.ime 20at 40 ~min.) ~ Conv.Mn Mw 17.6 2,3106,770 24.0 3,35010,900 135 31.6 4,71012,800 180 43.1 5,31014,500 25225 41.5 4,23015,500 ~..
i EyAMPTF. 2B
The procedure and techn~gues descrlbed for Ex~mple - 27 were repeated, except that n 30 cc bottle capped with - 30 a metal cap and a-Teflon~-coated slllcone dlsk, was used for the reaction. Rubber tubing, connected to N2 lnlet ` and outlet néedles, was used to purge the bottle of air, and a Teflon~-coated stir bar was used for agitation.
The empty bottle was charged with: 0.50 m moles 0N2BF4, 0.52 m moles NaOCN, and 50 m moles MMA. The bottle was ,~. , .
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, ~ ~ " , ' ' WO92/02561 2 0 8 8 7 8 2 PcT/USgl/0s331 then capped and N2-purged, then placed in a 35 oil bath. At t~0, 1 cc of N2-purged methanol was injected and samples were withdrawn with time.
., Reaction time at 35 (hr)% Conv. Mn Mw 1 21.7 9,230 83,800 2 34.7 9,900 128,000

3 44.4- 1~,400 200,000 Ex1~MpT~E 2 9 The procedure described for Ex mple 2B, lncluding the use of a 30 cc glass bottle, was repeated as follows, at 25. The 30 cc bottle was charged with:
0.40 m mole 0N2~F4 ~nd 40 m mole MMA. The bottle was sealed, N2 purged, and at t-0, ln~ected with a N2-purged ~; solution of 0.40 m mole 02N0N-NONa dlssolved in 0.8 cc H20. Samples were removed by syrlnge as follows.
... .
20Reaction time at 25 ( min.)~ Con~. Mn Mw 10.5 4,59011,400 lB.3 5,B8015,600 23.6 7,32019,000 25 120 33.2 7,92021,600 150 31.6 8,18022,300 180 32.2 9,04024,600 ,., =E~
; 30 ,P~M~ P-epa-ati~n To a 25 cc fllter flask, with a . . . .
Teflon~-coated stir bar, was charged 0.69 m mole 02N0N28F4, 0.24 m mole Na2N202, ~nd 57.8 m mole MMA. The ~, flask was sealed with-`a rubber septum ~nd a rubber dropper bulb and was purged with N2 using inlet and outlet needles. At t~0, 2 cc of N2-purged methanol was . .
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208~78~ 14 ~
injected, the flask was heated at 30 and stirred for three hours. The volatiles were then removed by ~acuum (0.1 mm Hg) stripping ~or 15 minutes at 25. The polymeric product (PMMA~ weighed 1.72 g. A 0.52 g portion of the PMMA was placed in a 30 cc crimp cap vial with a stir b~r,- was sealed with a ~eflon~-coated sillcone d~sk, and was purged wlth N2. Next, 5 cc of N2-purged BA and 2 cc of N2-purged acetone were ln~ected ~nd the resulting solutlon was stlrred at 30 for 3 hours. A 6.64 g postlon of the resultlng polymer was stripped of volatiles to give 1.03 g of polymer ~PMMA/PBA). The samples of PMMA and PMMA/PBA were ; characterized by lH NMR, GPC, and DSC ~differentlal scanning calorimetry).
lH NMR
~M~ Comparison of integrals for peaks at 3.9 ppm fH3 CH3 ~CH2-C-CO2 CH3 and at 3.6 ppm ~ CH2-C
I

showed that the isolated PMMA contained < 7~ unreacted .
~ 25 P~ 2a~ Comparison of integrals at 4.0 ppm :~ H CH3 ~. ~ CH2-C ) and at 3.6 ppm ~CH2-C

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. showed that the ratio of PBA/PMMA was 1.1.
, -- ~ GPC Mn Mw ---. P~MA . 4,540 20,900 PMMA~PBA9,880 236,000 ~ .

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' WO 92/02561 PCrtUS91/0~;331 A 0.76 g s~mple of PMMA/PBA was dissolved in 10 cc THF, filtered reduced in volume to about S cc by v~cuum (o . 1 mm ag), then poured into rapldly stirred 30 cc of methanol. The precipitated polymer was collected by filtration and dried at 65D for 16 hours nt 15-20 lnches of H20 pressure. The flnal polymer ~PMMA/P~A) weighed 0.63 g. A DSC analysis showed two distlnct r~gions of phase tr~nsition; one at -37 ~PBA) ~nd one at ~122 (PM~A). The two transltlons show that the polymer was not a random copolymer, whlch would be expected to exhibit a single transitlon temperature midway between -37 and l122.

E~CA~ T .F 31 The procedure described for Example 30 was repeated, with the same periods of heating at 30, except for using the following amounts of reagents:
0.47 m mole 0N2BF4, 0.24 m mole Na2N202, and 52.9 m mole MMA. A 2 cc portlon of N2-purged methanol was used in the preparation of PMMA. A 0.42 g sample of PMMA was heated at 30 and stirred wlth 5 cc of N2-purged BA and 2 cc of N2-purged acetone for 3 hours to prepare the final PMMA/PBA. The PMMA/PBA polymer was characterized by lH NMR and GPC. The comparlson of proton lntegrals for MMA (3.9 ppm) and PMMA (3.6 ppm) ln the PMMA polymer showed a MMA/PMMA ratio of about 8/92. The PBA/PMMA
ratio in the final polymer was about S/l. T~e GPC
analyses of the polymers gave the following:

:` Mn M~ -P~MA 2,890 9,220 -- PMMA/PBA 3,900 16,300 .

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2~8782 16 To a 30 cc glass bottle was charged: 0.40 m mole 0N2BF4, 0.40 m mole Na2N202, and 20 m mole EHMA and a Teflon0-coated stir bar. The bottle was sealed uslng a Teflon~-coated silicone dlsk and the contents were - N2-purged using needles connected to a N2 source and an oil bubbler. At t-0, 0.8 cc of N2-purged met~anol was in~ected by syringe. At t-2 ~ours, about l cc of reaction llquld w~s removed by ~yrlnge for analys~s by lH NMR and GPC. At t-2 bours a N2-purged ~olutlon of 17.~ m mole MAA in 5 cc of THF was ln~ected and the resulting solution was stirred for an additional 20 ~- hours.
The flnal polymer was purified by dissolving the reaction product in about 5 cc of THF, followed by pouring lnto 50 cc methanol. A milky suspenslon resulted, even on cooling to 0, so the solvent was ; allowed to evaporate, by standing ln a fume hood for about 16 hours. A 3.54 g sample of tan solid resulted. - -The tan solld was dissolved ln about 5 cc of THF, ~; followed by pouring into 50 cc of heptane. A
:~ precipitate was collected by flltration, was air drled, and weighed 2.12 g. The PE~MA and PEHMA//PEHMA~PMAA
polymers were analyzed by lH NMR, GPC, and acld tltration for PMAA content. Comparison of the lH NMR
~: lntegral for EHMA, 4.0 ppm : . . - . .
... ICH3 . .. .
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WO92/02561 2 0 8 8 7 8 2 PCT/US91/~5331 ,. . . .

PEHMAf 3.8 ppm ( - CH2-C
CO2- CH2 -CH(C2Hs)C~Hg .
showed a EHMA/PEHMA ratio of 5~3, or 37~ convers~on of EH~A to PEHMA, ln the 2 hour s~ple. A lH NMR ~pectrum of the final PEHMA//PE~MA/PMAA polymer showed the presence of only a trace oS resldual EHMA.

GPC Mn M~
PMMA -3,220 lB,200 PMMA/PBA 28,700 56,200 An acid titration was done to detcrmlne the ~mount of MAA in the final polymer. A 0.146 g portion of the final polymer was dissolved in 5 cc THF ~nd 1 cc methanol, containing a drop of dilute phenolphthalein indicator solution. A total of 0.07 cc of 0.~5 N
aqueous NaOH solution was required to reach the end-point. The calculated equivalent we$gbt of the final polymer was 27B g/mole. The calculated ratlo of PEHMA
total/PMAA in the final polymer was 0.97.

To a 3 ml glass vial (A), containing Tcflon0-coated magnetic stir bar, was charged 0.0465 q ~0.31 mmole) AgOCN, 0.0414 g (0.30 mmole) N-chlorosucclnimide, and 2 ml THF. ~he vial was sealed with a Teflon0-coated rubber septum by means-of a plastic screw cap and 22 gauge stainless needles were used to pa~s N2 through the vapor space for about 15-mlnutes. :~he contents of the vial were-stirred for 30 minutes, then the stirrer stopped to allow solids to settle to the bottom of the ~ial. A second 3 ml vial (B~, containing a Teflon~-~, - . .

,, .
, - .
' .~, 2 ~ 8 g 7 82 18 coated magnetlc stir bar, was charged wlth 1.07 ml ~10 mmole) MMA and was sealed wlth a Teflon0-coated rubber ~eptum and was purged with N2 for ~bout 15 minutes. At t~0, 0.67 ml of the clear llqu~d phase from vlal A was ln~ected lnto vlal B by syrlnge and the contents were stirred and heated ln a 50 oll bath for I -about 16 hours. ~he llquid in vlal B was then vacuum strlpped ~0.05 D) to remove volat$1es, glvlng rlse` to ~ol~d PMMA. A 3 ml glass vlal ~C), contalnlng a Teflon~-coated stir bar, was charged wlth 0.0368 g of PMMA ~vial B), 1 ml ~A, and 1 ml ethyl acetate. The vlal was sealed with a Teflon~-coated rubber septum, was purged with N2 for about 15 minutes and was stirred and heated at 90 for 70 minutes. The contents of vial C
were stripped ~0.05 mm) to remove volatlles, glvlng rise to PMMA/PBA. A lH NMR analysis of the PMMA/PBA showed the presence of PMMA (CH3-O, 3.9 ppm) a~d PBA
(C3H7- CH2 -O-, 4.0 ppm) in a mole ratio of PMMA/PBA ~
1/9.~. Samples of PMMA (vial B) and PMMA/PBA (vlal C) ; 20 were analyzed by GPC.
., .
GPC M~ M~
PMMA53,000 144,000 PMMA/PBA 193,000 1,050,000 ~_ The GPC elutlon curves for both polymers exhibited monomodal behavior. A 0.0274 g sample of PMMA (vlal B), was comblned with 1 ml of BA-and 1 ml of ethyl acetate and was heated under N2 for 20 hours at 45. A lX NMR
analysis of the final solution showed the presence of no significant PBA.
- Although preferred embodiments of the invention -- have been descrlbed hereinabove, lt is to be understood ~- that there is no intention to limit the inventlon to the 3~ precise constructions herein disclosed, and lt ls to be - - - - - - - - - - - - - . ......................... . .. .
. . . ' ~19 . i further understood that the right is reserved to all changes coming within the iscope of the invention as defined by the appended claims.

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Claims (39)

What is claimed is:

1. A process for the polymerization of vinyl monomers, comprising, contacting:
(a) an acrylic monomer or N-phenylmaleimide;
(b) a diazotate of the formula Ar1-N=N-O- M+, or a cyanate of the formula MOCN, or a hyponitrite of the formula M2N2O2, wherein Ar1 is aryl or substituted aryl, and M is a metal or a tetrahydro-carbylammonium ion; and (c) N-chlorosuccinimide, N-bromosuccinimide, or a diazonium salt of the formula Ar2N2+ X-, wherein Ar2 is aryl or substituted aryl, and X is an anion.

2. The process as recited in Claim 1 wherein said (a) component is a compound of the formula wherein the open valence is attached to a hydrocarbyloxy or substituted hydrocarbyloxy group, or a hydroxy group, and R3 is an alkyl group containing up to 4 carbon atoms or hydrogen.

3. The process as recited in Claim 2 wherein said R3 is hydrogen or methyl.

4. The process as recited in Claim 3 wherein said (a) component is acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, phenyl acrylate, cyclohexyl methacrylate, 2-hydroxyethyl acrylate, or 2-hydroxyethyl methacrylate.

5. The process as recited in Claim 1 wherein said M is an alkali metal or tetraalkylammonium.

6. The process as recited in Claim 1 wherein said Ar1 contains one or more electron withdrawing substituents.

7. The process as recited in Claim 1 wherein said Ar1 is p-nitrophenyl or p-cyanophenyl.

8. The process as recited in Claim 7 wherein said M is an alkali metal or tetraalkylammonium.

9. The process as recited in Claim 1 wherein said Ar2 is derived from benzene.

10. The process as recited in Claim 9 wherein said Ar2 is phenyl, or p-nitrophenyl.

11. The process as recited in Claim 8 wherein said Ar2 is phenyl or p-nitrophenyl.

12. The process as recited in Claim 1 wherein said (b) component is said diazotate.

13. The process as recited in Claim 1 wherein said (b) component is said cyanate.

14. The process as recited in Claim 1 wherein said (b) component is said hyponitrite.

15. The process as recited in Claim 1 wherein said (c) component is said diazonium salt.

16. The process as recited in Claim 1 wherein said (c) component is N-chlorosuccinimide or N-bromo-succinimide.

17. The process as recited in Claim 1 wherein said X is chloride, hexafluorophosphate, hexafluoro-antimonate, or tetrafluoroborate.

18. The process as recited in Claim 15 wherein said X is chloride, hexafluorophosphate, hexafluoro-antimonate, or tetrafluoroborate.

19. The process as recited in Claim 1 wherein the temperature is about -20°C to about 120°C.

20. The process as recited in Claim 19 wherein said temperature is about 0°C to about 60°C.

21. The process as recited in Claim 20 wherein said temperature is about 10°C to about 40°C.

22. The process as recited in Claim 1 carried out in solution.

23. The process as recited in Claim 1 carried out as a suspension.

24. The process as recited in Claim 23 wherein said suspension is an aqueous suspension.

25. The process as recited in Claim 1 carried out as an emulsion.

26. The process as recited in Claim 25 wherein said emulsion is an aqueous emulsion.

27. The process as recited in Claim 1 wherein a block copolymer is produced.

28. The process as recited in Claim 1, comprising the further step of a secondary polymerization.

29. The process as recited in Claim 28 wherein said secondary polymerization is carried out at about 80°C to about 120°C.

30. The process as recited in Claim 3, comprising the further step of a secondary polymerization.

31. The process as recited in Claim 28, wherein the product is a block copolymer.

32. The process as recited in Claim 30, wherein he product is a block copolymer.

33. The product of the process of Claim 1.

34. The product of the process of Claim 3.

35. The product of the process of Claim 11.

36. The product of the process of Claim 28.

37. The product of the process of Claim 30.

38. The process as recited in Claim 29 wherein said secondary polymerization is carried out at about 90°C to about 100°C.

39. The process as recited in Claim 5 wherein said M is sodium, potassium or tetraalkylammonium.