PROTECTION AND POLYMERIZATION OF FUNCTIONAL MONOMERS .18. SYNTHESES OF WELL-DEFINED POLY(VINYLPHENOL), POLY[(VINYLPHENYL)METHANOL], AND POLY[2-(VINYLPHENYL)ETHANOL] BY MEANS OF ANIONIC LIVING POLYMERIZATION OFSTYRENE DERIVATIVES CONTAINING TERT-BUTYLDIMETHYLSILYL ETHERS

Anionic polymerization behaviors of nine styrene derivatives with hydr oxy functions protected with tert-butyldimethylsilyl groups, e.g., ter t-butyldimethylsilyl ethers of 4-vinylphenol (1a), (4-vinylphenyl)-met hanol (2a), 2-(4-vinylphenyl)ethanol (3a), and their meta (1b-3b) and ortho isomers (1c-3c), have been examined with various anionic initiat ors in THF at -78-degrees-C. Among them, 1a,b, 2b, and 3a-c undergo an ionic polymerization without chain-transfer and termination reactions to afford stable living polymers. The resulting polymers all are found to possess molecular weights predictable from [monomer] to [initiator ] ratios and narrow molecular weight distributions, the values of M(w) BAR/M(n)BAR being around 1.1. Deprotection of the silyl groups from th ese polymers provides well-defined linear polystyrenes with either phe nolic or alcoholic hydroxy groups. As expected, they are shown to reta in desirable characteristics of their parent living polymers, e.g., co ntrollable molecular weights and narrow molecular weight distributions . By contrast, attempts to polymerize the structurally analogous 1c, 2 a, and 2c have failed. No appreciable polymerization occurs with these monomers under the identical conditions used in the successful polyme rizations. The mechanisms for side reactions in the unsuccessful polym erizations are proposed.