Hydrosilylation has been carried out between Si-H terminated polydimethylsiloxanes with narrow molecular weight distribution and protected 3-allyloxy-l,2-propanediol, and after subsequently alcoholyzed, α-{3-[(2,3-dihydroxy)propoxy]propyl}-ω- butyl-polydimethylsiloxanes with varying number of ((Si(CH3)2-O) unit were obtained. At each step, the produced compounds were carefully characterized. The results showed that each step was successfully carried out and target products were achieved.
Xiao Li Zhan Zhen Huan Luo Qing Hua Zhang Bi Chen Feng Qiu Chen
The reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization of vinyl acetate (VAc) mediated by methyl (methoxycarbonothioyl) sulfanyl acetate (MMSA) was carried out. The results showed that polymerizations initiated by AIBN and KPS proceeded in a controlled way. The RAFT miniemulsion polymerization of VAc initiated by KPS showed the shorter inhibition period, higher propagation rate coefficient and final conversion than those in experiment initiated by AIBN. When the monomer conversion reached 25%, the polydispersity index (PDI) of polymer became broad, which was related to chain transfer reaction in RAFT miniemulsion of VAc.
Bo Jiang Qing Hua Zhang Xiao Li Zhan Feng Qiu Chen
Polystyrene-styrene/butadiene diblock copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization.During the polymerization process,the molecular weight distribution was narrow and the numerical molecular weight of the copolymers increased with increasing conversion of monomers,which was close to the theoretical.FT-IR and ^1H NMR results indicated that the microstructure of the polymer was mainly 1,4-trans-butadiene with small amount of 1,2-units,and composition in the copolymers was obtained.
Zhen Xi WangQing Hua ZhangYi Tao YuXiao Li ZhanFeng Qiu ChenJi Hai Xiong