It was demonstrated that the fast RAFT polymerization of styrene with almost perfect polymerization performance could be achieved by using a carefully designed miniemulsion polymerization system.With much higher level...It was demonstrated that the fast RAFT polymerization of styrene with almost perfect polymerization performance could be achieved by using a carefully designed miniemulsion polymerization system.With much higher levels of surfactant (9 wt% based on monomer) and co-stabilizer (5 wt% based on monomer) than those in typical miniemulsion polymerization,the miniemulsion polymerization using 1-phenylethyl phenyl-dithioacetate as a RAFT agent showed a very fast polymerization rate,excellent performance of living radical polymerization during the entire polymerization process,and narrow particle size distributions.It was concluded that RAFT miniemulsion polymerization presented an excellent commercial process for a living radical polymerization system.展开更多
The methyl methacrylate(MMA) reversible addition-fragmentation chain transfer(RAFT) miniemulsion polymerization in the presence of β-cyclodextrin(β-CD) was investigated. β-CD is found to act both as an efficient so...The methyl methacrylate(MMA) reversible addition-fragmentation chain transfer(RAFT) miniemulsion polymerization in the presence of β-cyclodextrin(β-CD) was investigated. β-CD is found to act both as an efficient solubilizer for RAFT agent(2-cyanopro-2-yl dithiobenzoate) and as a stabilizer for heterogeneous polymerization. The RAFT miniemulsion polymerizations with or without β-CD were compared in terms of kinetics and the molecular weight distribution. The problem of poor latex stability was observed in this system. A good result of the control over RAFT miniemulsion polymerization of MMA was obtained with β-CD. The increase of the molecular weight of poly(methyl methacrylate) shows a linear relationship with the monomer conversion. The polydispersity index of the polymer with β-CD(PDI=1.18—1.21) is smaller than that without β-CD. TEM photographs showed that the PMMA particles produced with β-CD had smooth surfaces and uniform particle size. Higher amount of sodium dodecyl sulfate and hexadecane was found in favor of improving the controllability of the system. Oil soluble initiator is beneficial to the controllability of the polymerization.展开更多
文摘It was demonstrated that the fast RAFT polymerization of styrene with almost perfect polymerization performance could be achieved by using a carefully designed miniemulsion polymerization system.With much higher levels of surfactant (9 wt% based on monomer) and co-stabilizer (5 wt% based on monomer) than those in typical miniemulsion polymerization,the miniemulsion polymerization using 1-phenylethyl phenyl-dithioacetate as a RAFT agent showed a very fast polymerization rate,excellent performance of living radical polymerization during the entire polymerization process,and narrow particle size distributions.It was concluded that RAFT miniemulsion polymerization presented an excellent commercial process for a living radical polymerization system.
文摘The methyl methacrylate(MMA) reversible addition-fragmentation chain transfer(RAFT) miniemulsion polymerization in the presence of β-cyclodextrin(β-CD) was investigated. β-CD is found to act both as an efficient solubilizer for RAFT agent(2-cyanopro-2-yl dithiobenzoate) and as a stabilizer for heterogeneous polymerization. The RAFT miniemulsion polymerizations with or without β-CD were compared in terms of kinetics and the molecular weight distribution. The problem of poor latex stability was observed in this system. A good result of the control over RAFT miniemulsion polymerization of MMA was obtained with β-CD. The increase of the molecular weight of poly(methyl methacrylate) shows a linear relationship with the monomer conversion. The polydispersity index of the polymer with β-CD(PDI=1.18—1.21) is smaller than that without β-CD. TEM photographs showed that the PMMA particles produced with β-CD had smooth surfaces and uniform particle size. Higher amount of sodium dodecyl sulfate and hexadecane was found in favor of improving the controllability of the system. Oil soluble initiator is beneficial to the controllability of the polymerization.
