Hydrosilylation has been carried out between Si-H terminated polydimethylsiloxanes with narrow molecular weight distribution and protected 3-allyloxy-1,2-propanediol,and after subsequently alcoholyzed,α-{3-[(2,3-dihydroxy)propoxy]propyl}-ω-butyl -polydimethylsiloxanes with varying number of((Si(CH_3)_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
Reversible addition fragmentation chain transfer(RAFT)mediated miniemulsion copolymerizations of butyl methacrylate with fluoroacrylate were carried out at 70 ℃ with potassium persulphate as initiator,and the kinetics of copolymerizations were investigated.Copolymer compositions at low conversion levels were determined by 1H NMR spectra techniques.In the presence of RAFT agent 2-cyanoprop-2-yl dithiobenzoate(CPDB),the copolymerization of BMA with FMA in miniemulsion exhibited typical features of a controlled mole-cular weights and narrow polydispersities.The reactivity ratios were evaluated by Kellen-Tudos(K-T)method,which yields the apparent reactivity ratios,rBMA=0.63 and rFMA=0.79.The results show that the monomer FMA with a fluorinated side chain is more reactive than BMA,and the copolymerizations have a tendency to alternate and to produce a higher FMA content in the copolymers.The spontaneous statistical copolymers with soft gradient shapes were obtained using variable initial ratios of BMA and FMA.
