Photoinitiated copolymerization of <img src='/image/spc_char/alpha.gif' border=0>-terpineol and methylmethacrylate

Abstract

Free radical copolymerization of a-terpineol and methylmethacrylate (MMA) in xylene at 30±0.2°C using azobisisobutyronitrile (AIBN) as the photoinitiator for 27 h has been carried out. The kinetic expression is {<i style="">R</i>_p<img src='/image/spc_char/alpha.gif' border=0>[AIBN]^0.62, [<img src='/image/spc_char/alpha.gif' border=0>-terpineol]^1.2, [MMA]^1.5}. It is attributed to primary radical termination as well as degradative chain transfer reaction. Analysis of the copolymers by IR and NMR shows the presence of alcoholic and carboxyl group due to acrylate in the copolymer. The glass transition temperature of the copolymer, determined by differential scanning calorimetry, is 85°C. The alternating nature of the copolymer is confirmed by the product of the reactivity ratios <i style="">r</i>₁ [MMA] = 0.12 and <i style="">r</i>₂[<img src='/image/spc_char/alpha.gif' border=0>-terpineol] = 0.08. The Alfrey-Price, Q-e parameter for <img src='/image/spc_char/alpha.gif' border=0>-terpineol has been calculated as 0.282 and 1.82, respectively. A possible mechanism of the copolymerization has been proposed.