Copolymers, graft ether copolymerization

Although they lack commercial importance, many other poly(vinyl acetal)s have been synthesized. These include acetals made from vinyl acetate copolymerized with ethylene (43—46), propjiene (47), isobutjiene (47), acrylonitrile (48), acrolein (49), acrylates (50,47), aHyl ether (51), divinyl ether (52), maleates (53,54), vinyl chloride (55), diaHyl phthalate (56), and starch (graft copolymer) (47). 

These two macromonomers were subsequently copolymerized with styrene to yield graft copolymers 84) containing crown ethers in their side chains. 

The hydroxy-tempo derivative 11 is first reacted with p-chloromethyl styrene to give a Tempo capped polymerizable styrenic compound 12. Copolymerization of 12 with styrene gives the multifunctional initiator 13, which has a PS backbone with attached Tempo groups. Reaction of 13 with styrene at 130 °C gives the grafted copolymer 14. After cleavage of the benzyl ether bonds, a Mn of 23000 is determined with a Mw/Mn value of 1.20. 

For styrene-based random copolymers, functional groups can be introduced into the polymer chains via copolymerization with functional styrene derivatives, because the electronic effects of the substituents are small in the metal-catalyzed polymerizations in comparison to the ionic counterparts. Random copolymer R-6 is of this category, synthesized from styrene and />acetoxystyrene.372 It can be transformed into styrene// -vinylphenol copolymers by hydrolysis.380 The benzyl acetate and the benzyl ether groups randomly distributed in R-7 and R-8 were transformed into benzyl bromide, which can initiate the controlled radical polymerizations of styrene in the presence of copper catalysts to give graft copolymers.209 Epoxy groups can be introduced, as in R-9, by the copper-catalyzed copolymerizations without loss of epoxy functions, while the nitroxide-mediated systems suffer from side reactions due to the high-temperature reaction.317... 

These macromonomers were reacted with a halohydrin to yield phenyl glycidyl ether end-groups. Subsequent copolymerization with ethylene oxide or epichloro-hydrin, using the Vanderberg catalyst (triethylamine/water mixture) produced graft copolymers [187]. 

Ptobably the first graft copolymer was based on cellulose, Ushakov (33) who attached vinyl or allyl ethers to cellulose and used these sites to initiate the copolymerization with maleic acid esters. Another early paper was by Jahn (34). Graft polymerization of cellulose has been an active field, at least until recently, and well over a thousand papers and patents have been issued. 

These esters may be grafted to poly(ether-urethanes) either as homopolymers or copolymers by the procedure already outlined. In addition, they may be copolymerized directly with other vinyl monomers to give materials with a wide variety of properties. 

Maleic anhydride grafting (cont.) poly(styrene-co-divinylbenzene), 694 poly(styrene-co-isobutylene), 675, 689 poly(styrene-co-nfialeic anhydride), 676, 679 poly(vinyl acetate), 676, 694 poly(vinyl acetate-co-vinyl fluoride), 678 poly(vinyl alkyl ethers), 675, 679, 692, 701 poly(vinyl chloride), 683, 692, 693, 695, 702 poly(vinylidene chloride), 691 poly(vinyl toluene-co-butadiene), 689 radical—initiated, 459-462, 464-466, 471, 475, 476 radiation—initiated, 459, 461, 466, 471, 474 redox-initiated, 476 rubber, 678, 686, 687, 691, 694 to saturated polymers, 459-466, 475, 476 solvents used 460-463, 465, 466, 469, 474-476 styrene block copolymers, 679 tall oil pitch, 678, 697 terpene polymers, 679, 700 thermally-initiated, 462, 464-467, 469, 476 to unsaturated polymers, 459, 466-474 vapor-phase techniques, 464, 474, 475 to wool fibers, 476 Maleic anhydride monomer acceptor for complex formation, 207-210 acetal copolymerization, 316 acetone CTC thermodynamic constants, 211 acetone photo-adduct pyrolysis, 195, 196 acetylacetone reaction, 235 acetylenic photochemical reactions, 193-196 acrylamide eutectic mixtures, 285 acylation of aromatic acids, 97 acylation of aromatics, 91, 92 acylation of fused aromatics, 92, 95, 97, 98 acylation of olefins, 99 acylation of phenols, 94-96 acylic diene Diels-Alder reactions, 104-111, 139 addition polymer condensations, 503-505 adduct with 2-cyclohexylimino-cyclopentanedi-thiocarboxylic acid, 51 adducts for epoxy resins curing, 507-510 adduct with 2-iminocyclopentanedithiocarboxylic acid, 51... 

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