Anionic polymerizations of 1-adamantyl methacrylate and 3-methacryloyloxy-1,1′-biadamantane

Anionic polymerizations of 1-adamantyl methacrylate (1) and 3-methacryloyloxy-1,1'-biadamantane (2) were carried out in the THF at -50 to -78degreesC for 24 h. The initiator employed was either [1,1-bis(4'-trimethylsilylphenyl)-3-methylpentyl]lithium (3)/lithium chloride, or diphenylmethylpotassium. The polymerization of 1 and 2 proceeded quantitatively to afford the polymers having the predicted molecular weights based on the molar ratios of monomers and initiators and the narrow molecular weight distributions (M-w/M-n = 1.05-1.18), indicating the living character of the polymerization systems of 1 and 2. Novel well-defined block copolymers, poly[2-block-(tert-butyl methacrylate)], poly(2-block-isoprene-block-2), and poly-[[(2,2-dimethyl-1,3-dioxolan-4-yl)methyl methacrylate]-block-2], were anionically synthesized by the sequential copolymerization of 2 and comonomers. The poly(2) had the significantly higher glass transition temperature (T-g) of 236degreesC and decomposed over 370degreesC, while poly(1) started to decompose at around 320degreesC before its T-g was reached. This thermal stability can be explained by the substituent effects of the bulky adamantyl and 1,1'-biadamantyl moieties.