ABSTRACT:p-Phenylselenomethylstyrene (1) as a new selenium-containing vinyl monomer was prepared. It was readily polymerized free radically in the presence of 2,2'-azobis(isobutyronitrile) (AIBN) as initiator at 60°C to afford corresponding homopolymers having number-average molecular weights of about 8600. From the copolymerization of 1 with styrene, Q and e of 1 were 1.40 and -1.06, respectively. Photoirradiation of the copolymer of styrene and 1 in the presence of methyl methacrylate effectively afforded a graft copolymer composed of a polystyrene backbone and poly(methyl methacrylate) branches.

No abstract

No abstract

ABSTRACT:The photopolymerization of styrene with benzyl phenyl selenide proceeded smoothly to give polystyrene having benzyl and phenylsclcno groups at a-and w-chain ends, respectively, and the degree of functionality was 0.95. In a limited range of conversion, both the polymer yields and number average of molecular weights (M.) increased with the reaction time and the M. linearly increased with yield. The addition of styrene to the polystyrene with irradiation increased the molecular weight of the polymer. In the photopolymerization of methyl methacrylate, similar polymerization behavior was observed. The tacticity of the poly(methyl methacrylatc) was in good agreement with that prepared by radical mechanism. Photoirradiation of polystyrene having phenylseleno group at the w-end in the presence of methyl methacrylate effectively afforded a block copolymer of styrene and methyl methacrylate.KEY WORDS Radical Polymerization / Benzyl Phenyl Selenide / p-Methoxybenzyl p-Trimethylsilylphenyl Selenide / Photoiniferter / Polymeric Photoiniferter / Block Copolymer / End functional polymers are useful precursors for novel block, graft and star polymers. The synthesis of end functional polymers are conventionally prepared by anionic, cationic, and radical polymerization. 1 -11 Preparation by radical polymerization with iniferter method is quite convenient and hence widely used. 12 -16 Otsu and coworkers 1 7 -19 proposed iniferter for the design of the polymer chain end structure. An iniferter is an initiator which also functions as chain transfer agent and/or primary radical terminator. It is attractive for preparing simple block copolymers and more complex polymer architectures using various monomers which do not polymerize by an ionic mechanism. 20 -23 Iniferters mainly use organic sulfur compounds such as tetraalkylthiuram disulfides, dithiocarbamates, and tetramethylene disulfide.We recently reported that photopolymerization of styrene in the presence of di phenyl diselenide, 24 similar to the case of tetraalkylthiuram disulfides 25 to afford polystyrene carrying phenylseleno groups at both chain ends (P-A) (eq I). By the irradiation of light to the polymers with selenide moieties (P-A) in styrene, polystyrene with higher molecular weight (P-B) was obtainOse-Se-Q + n P-A + m CH2=3

No abstract