Polyurethane elastomers derived from 4,4 ' -methylene bis(phenyl isocyanate), butylene glycol and the low oxyethylene moiety content copolyether of tetrahydrofuran and ethylene oxide, obtained by copolymerization ...Polyurethane elastomers derived from 4,4 ' -methylene bis(phenyl isocyanate), butylene glycol and the low oxyethylene moiety content copolyether of tetrahydrofuran and ethylene oxide, obtained by copolymerization using heteropolyacid-ethylene oxide initiator system, were prepared. The polyurethanes exhibited an increased water absorption and much better low temperature resilience, which remained high even at a temperature of -3 degreesC, while that of polyurethane based upon poly(tetramethylene ether) glycol of the 'same molecular weight, i.e. being 2000, and molecular weight distribution, i.e, in the range of 1.4-1.5, starts to decrease dramatically at 5 degreesC.展开更多
The novel biodegradable copolymer PDLLA-（MAH-Diol）n-PDLLA with unsaturated bond was synthesized by copolymefizing lactide and prepolymer, which was prepared by the polycondensation of maleic anhydride and poly（ethy...The novel biodegradable copolymer PDLLA-（MAH-Diol）n-PDLLA with unsaturated bond was synthesized by copolymefizing lactide and prepolymer, which was prepared by the polycondensation of maleic anhydride and poly（ethylene glycol）, using ptoluene sulphonic acid as catalyst. The new copolymer has improved hydrophilicity and flexibility. The structure and properties of the novel polymers were studied by FTIR, NMR, GPC-MALLS and DSC.展开更多
基金This work was financially supported by the Doctoral Program Foundation of Institution of High Education.
文摘Polyurethane elastomers derived from 4,4 ' -methylene bis(phenyl isocyanate), butylene glycol and the low oxyethylene moiety content copolyether of tetrahydrofuran and ethylene oxide, obtained by copolymerization using heteropolyacid-ethylene oxide initiator system, were prepared. The polyurethanes exhibited an increased water absorption and much better low temperature resilience, which remained high even at a temperature of -3 degreesC, while that of polyurethane based upon poly(tetramethylene ether) glycol of the 'same molecular weight, i.e. being 2000, and molecular weight distribution, i.e, in the range of 1.4-1.5, starts to decrease dramatically at 5 degreesC.
文摘The novel biodegradable copolymer PDLLA-（MAH-Diol）n-PDLLA with unsaturated bond was synthesized by copolymefizing lactide and prepolymer, which was prepared by the polycondensation of maleic anhydride and poly（ethylene glycol）, using ptoluene sulphonic acid as catalyst. The new copolymer has improved hydrophilicity and flexibility. The structure and properties of the novel polymers were studied by FTIR, NMR, GPC-MALLS and DSC.
