A novel hydroxy-capped comb-like block polymer, poly[poly(ethylene glycol)](HCPEG), was prepared via atom transfer radical polymerization(ATRP) of α-methylacryloyl-ω-hydroxyl-poly(ethylene glycol). The polymerizatio...A novel hydroxy-capped comb-like block polymer, poly[poly(ethylene glycol)](HCPEG), was prepared via atom transfer radical polymerization(ATRP) of α-methylacryloyl-ω-hydroxyl-poly(ethylene glycol). The polymerization kinetics of the PHPEGMA was studied by gel permeation chromatography and 1H NMR. The semilogarithmic plot of monomer conversion vs. reaction time increases linearly before the conversion is up to more than 70% and the number-average molecular weights(M_n) by GPC increased linearly with increase of the monomer conversion up to 100%, while the polydispersity index remained fairly narrow with M_w/M_n<1.2.展开更多
PEGylated poly（2-（dimethylamino）ethyl methacrylate） with comb-like architecture was synthesized by two-step polymerization. First,poly（oligo（ethylene glycol） malicate）（POEGMA） bearing pendant hydroxyl groups...PEGylated poly（2-（dimethylamino）ethyl methacrylate） with comb-like architecture was synthesized by two-step polymerization. First,poly（oligo（ethylene glycol） malicate）（POEGMA） bearing pendant hydroxyl groups was prepared by direct polycondensation of oligo（ethylene glycol） and malic acid in the presence of scandium triflate as chemoselective catalyst.Then the poly（2- （dimethylamino）ethyl methacrylate） side chains were grafted from the POEGMA backbone by atom transfer radical polymerization （ATRP） after the hydroxyl groups were modified into bromo-ester form,resulting in a PEGylated cationic copolymer with branched architecture.展开更多
Comb-like polyethylene（PE） was prepared via anionic polymerization combined with ＂graft-onto＂ process. The polybutadiene（PB） backbone underwent hydroxylation at 1,2-vinyl groups to obtain a controlled number of ...Comb-like polyethylene（PE） was prepared via anionic polymerization combined with ＂graft-onto＂ process. The polybutadiene（PB） backbone underwent hydroxylation at 1,2-vinyl groups to obtain a controlled number of hydroxyl groups along the main chain. After the translation of hydroxyl groups to tosyl groups, a nucleophilic substitution by living anionic PB chains was achieved. The comb PE was finally obtained by the hydrogenation of the obtained unsaturated comb polymer. Since the living anionic polymerization was used to prepare the backbones and the branch chains, molecular weight to molecular weight distribution（Mw/Mn〈1.5） can be well-controlled in the final comb polymer, including the average number and length of branches.展开更多
A new comblike polymer host for polymer electrolyte was synthesized by reacting monomethyl ether of poly(ethylene glycol) with poly(vinyl methyl ether-alt-maleic anhydride) and endcapping the residual carboxylic acid ...A new comblike polymer host for polymer electrolyte was synthesized by reacting monomethyl ether of poly(ethylene glycol) with poly(vinyl methyl ether-alt-maleic anhydride) and endcapping the residual carboxylic acid with methanol. Butanone was selected as a solvent for the esterification in order to obtain a completely soluble product. The synthesis process was traced through by LR. Compared with the model compounds, the presumed structure of this comblike polymer has been proved to be valid by C-13 NMR The comb polymer is a white rubbery solid. It can be dissolved in butanone and THF, and manifests good film forming ability.展开更多
Three-dimensional Monte Carlo simulations of comb-like polymer chains with various backbone lengths Nb, arm lengths Na and arm densities m are carried out to study the elastic behavior of comb-like polymer chains. The...Three-dimensional Monte Carlo simulations of comb-like polymer chains with various backbone lengths Nb, arm lengths Na and arm densities m are carried out to study the elastic behavior of comb-like polymer chains. The radius of gyration, the shape factors and bond length in different cases during elastic process are calculated, and it is found that the comb-like polymer molecules with longer backbone or shorter arm are more close to linear chains. But the arm density rn affects the chain conformation non-monotonously. Some thermodynamic properties are also studied. Average Helmholtz free energy and elastic force fall increase with elongation ratio 2 for all chains.展开更多
文摘A novel hydroxy-capped comb-like block polymer, poly[poly(ethylene glycol)](HCPEG), was prepared via atom transfer radical polymerization(ATRP) of α-methylacryloyl-ω-hydroxyl-poly(ethylene glycol). The polymerization kinetics of the PHPEGMA was studied by gel permeation chromatography and 1H NMR. The semilogarithmic plot of monomer conversion vs. reaction time increases linearly before the conversion is up to more than 70% and the number-average molecular weights(M_n) by GPC increased linearly with increase of the monomer conversion up to 100%, while the polydispersity index remained fairly narrow with M_w/M_n<1.2.
基金the financial supports from the Major State Basic Research Project(No. 2011CB606001)the Committee of Science and Technology of Zhejiang Provincea project supported by Scientific Research Fund of Ztiejiang Provincial Education Department(No.Y201121828)
文摘PEGylated poly（2-（dimethylamino）ethyl methacrylate） with comb-like architecture was synthesized by two-step polymerization. First,poly（oligo（ethylene glycol） malicate）（POEGMA） bearing pendant hydroxyl groups was prepared by direct polycondensation of oligo（ethylene glycol） and malic acid in the presence of scandium triflate as chemoselective catalyst.Then the poly（2- （dimethylamino）ethyl methacrylate） side chains were grafted from the POEGMA backbone by atom transfer radical polymerization （ATRP） after the hydroxyl groups were modified into bromo-ester form,resulting in a PEGylated cationic copolymer with branched architecture.
基金Supported by the National Natural Science Foundation of China（Nos.51073149, 51233005）.
文摘Comb-like polyethylene（PE） was prepared via anionic polymerization combined with ＂graft-onto＂ process. The polybutadiene（PB） backbone underwent hydroxylation at 1,2-vinyl groups to obtain a controlled number of hydroxyl groups along the main chain. After the translation of hydroxyl groups to tosyl groups, a nucleophilic substitution by living anionic PB chains was achieved. The comb PE was finally obtained by the hydrogenation of the obtained unsaturated comb polymer. Since the living anionic polymerization was used to prepare the backbones and the branch chains, molecular weight to molecular weight distribution（Mw/Mn〈1.5） can be well-controlled in the final comb polymer, including the average number and length of branches.
文摘A new comblike polymer host for polymer electrolyte was synthesized by reacting monomethyl ether of poly(ethylene glycol) with poly(vinyl methyl ether-alt-maleic anhydride) and endcapping the residual carboxylic acid with methanol. Butanone was selected as a solvent for the esterification in order to obtain a completely soluble product. The synthesis process was traced through by LR. Compared with the model compounds, the presumed structure of this comblike polymer has been proved to be valid by C-13 NMR The comb polymer is a white rubbery solid. It can be dissolved in butanone and THF, and manifests good film forming ability.
基金supported by the National Natural Science Foundation of China(No.20704033)
文摘Three-dimensional Monte Carlo simulations of comb-like polymer chains with various backbone lengths Nb, arm lengths Na and arm densities m are carried out to study the elastic behavior of comb-like polymer chains. The radius of gyration, the shape factors and bond length in different cases during elastic process are calculated, and it is found that the comb-like polymer molecules with longer backbone or shorter arm are more close to linear chains. But the arm density rn affects the chain conformation non-monotonously. Some thermodynamic properties are also studied. Average Helmholtz free energy and elastic force fall increase with elongation ratio 2 for all chains.
