Hydrogenated poly(styrene-co-α-methylstyrene) polymers:: A new class of high glass-transition-temperature polyolefins

We demonstrate a method to prepare high glass-transition-temperature (T-g) materials with a two-step process-anionic copolymerization of a-methylstyrene with styrene (leading to copolymers referred to as SAMS), with subsequent catalytic hydrogenation. The product, poly(cyclohexyl ethylene-co-2-cyclohexyl propylene), is referred to as PCEPx, where the subscript denotes the molar percentage of 2-cyclohexyl propylene units in the copolymer. PCEPx exhibits T-g values between 140 and 178 degreesC depending on the composition and composition distribution in the polymerization product. To increase the toughness of PCEPx, we copolymerized SAMS with butadiene followed by hydrogenation to form PCEPx/PEEy block copolymers, where PEEy refers to poly(ethylene-co-ethyl ethylene), and y denotes the molar percentage of ethyl ethylene segments. T-g values as high as 162 degreesC were achieved for these block copolymers. (C) 2003 Wiley Periodicals, Inc.