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
Living" radical polymerization of methyl methacrylate was investigated using a new initiating system, i.e. DCDPS/FeCl 3/PPh 3, in which diethyl 2,3 dicyano 2,3 diphenyl succinate(DCDPS) is a hexa substituted etha...Living" radical polymerization of methyl methacrylate was investigated using a new initiating system, i.e. DCDPS/FeCl 3/PPh 3, in which diethyl 2,3 dicyano 2,3 diphenyl succinate(DCDPS) is a hexa substituted ethane thermal iniferter. The polymerization mechanism belongs to a reverse ATRP process. The polymerization was closely controlled in bulk at 75 ℃, polymethyl methacrylate(PMMA) with a high molecular weight and quite narrow polydispersity ( M w/ M n=1 20—1 29) was obtained. End group analysis by 1H NMR spectroscopy shows that the resulting PMMA is ω functionalized by a chlorine atom, which is also confirmed by the chain extension reaction in the presence of CuCl/bipy catalyst via a conventional ATRP process. [WT5HZ]展开更多
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.
文摘Living" radical polymerization of methyl methacrylate was investigated using a new initiating system, i.e. DCDPS/FeCl 3/PPh 3, in which diethyl 2,3 dicyano 2,3 diphenyl succinate(DCDPS) is a hexa substituted ethane thermal iniferter. The polymerization mechanism belongs to a reverse ATRP process. The polymerization was closely controlled in bulk at 75 ℃, polymethyl methacrylate(PMMA) with a high molecular weight and quite narrow polydispersity ( M w/ M n=1 20—1 29) was obtained. End group analysis by 1H NMR spectroscopy shows that the resulting PMMA is ω functionalized by a chlorine atom, which is also confirmed by the chain extension reaction in the presence of CuCl/bipy catalyst via a conventional ATRP process. [WT5HZ]
