Glycidyl methacrylate anionic polymerization

The chain tacticity of PMMA synthesized by GTP catalyzed by nucleophiles at different temperatures was analyzed by Webster and coworkers The syndiotactic content increases from 50% at 60 °C up to 80% at —90°C in THF, using tris(dimethylamino)sulfonium bifluoride [(Me2N)3S+ HF2 ] as catalyst . In contrast to the anionic polymerization of MMA, the stereoselectivity of GTP is less sensitive to solvent. It must be noted that PMMA is less syndiotactic when the GTP is catalyzed by nucleophiles rather than by Lewis acids . GTP was extended to the living polymerization of many acrylates and methacrylates, such as nBuMA, glycidyl-MA, 2-ethylhexyl-MA, Me3SiOCH2CH2-MA, sorbyl-MA, allyl-MA, lauryl-MA), acrylates (EA, BuA), acrylonitrile, methacrylonitrile and Al,A-dimethylacrylamide . 

Choice of Support. The most commonly used organic support is polystyrene (cross-linked with DVB) in its microp-orous (1-2% cross-linking) form, although it has also been used in its macroporous and popcorn form (Ford et al, 1982 Shan et al.,1989). Various other polymeric catalysts have been used like polyvinylpyridine resins, commercial ion-exchange resins (Arrad and Sasson, 1989), modified dextran anion exchangers (Kise et al, 1981), and macroporous glycidyl methacrylate-ethylene dimethacrylate resins (Hradil and Svec,... 

Detailed descriptions of polymerizations of MMA, ethyl aerylate, and butyl acrylate with either anionic or Lewis aeid eatalysts are given in Refs. [156] and [234]. Various other monomers, including lauryl, glycidyl, 2-ethylhexyl, 2-trimethylsiloxyethyl, sorbyl, allyl, and 2-(allyloxy)ethyl methacrylates have been employed in GTP [234]. Because of the milder conditions, this polymerization method is generally much more suitable than the classical anionic polymerization for monomers with reaetive functional groups. 

Allyl group containing polymers have been found to cross-link readily on e-beam exposure. Free radical solution polymerization of allyl methacrylate has been shown to result in a unique polymer with about 65% pendant allyl groups and the remainder believed to be involved in a cyclization propagation step. The exact structure of this polymer has yet to be established however, it differs significantly in physical properties from anionically prepared poly(allyl methacrylate), which has a structure with 100% pendant allyl groups. The of the former polymer is llO C, compared to the latter, which is 36 The free radically prepared polymer is very sensitive to e-beam radiation (1.5 X 10"Ccm" at lOkeV) but has poor physical properties such as adhesion, etc. Copolymerization of allyl methacrylate with glycidyl methacrylate results in copolymers with equivalent... 

---