Poly（d,l-lactide-co-p-dioxanone） （P（LA-co-PDO）） copolymers with different chain microstructures were synthesized by onestep or two-step bulk ring-opening polymerizations of d,l-lactide （LA） and p-dioxanone （...Poly（d,l-lactide-co-p-dioxanone） （P（LA-co-PDO）） copolymers with different chain microstructures were synthesized by onestep or two-step bulk ring-opening polymerizations of d,l-lactide （LA） and p-dioxanone （PDO） monomers using stannous octoate [Sn（Oct）2]/n-dodecanol as the initiating system. The average sequence lengths of the lactidyl （LLA） and dioxanyl （LpDo） units were calculated from the ^1H NMR spectra. It was found that both LLA and Lpoo values from the two-step syntheses were significantly longer than those from the corresponding one-step syntheses, indicating more blocky structure achieved for the twostep copolymers. Corresponding to this difference in microstructure, the two-step copolymers were semi-crystalline, while the one-step copolymers were completely amorphous. In conclusion, the crystallinity of P（LA-co-PDO） copolymers could be adjusted conveniently to meet specific applications by changing the microstructure of the copolymers via different polymerization routes.展开更多
A novel poly（ethylene glycol） （PEG） analogue composed of aliphatic polyester backbone and pendant oligo（ethylene glycol） short chains is reported. The PEG analogue is a copolymer synthesized by ring-opening alte...A novel poly（ethylene glycol） （PEG） analogue composed of aliphatic polyester backbone and pendant oligo（ethylene glycol） short chains is reported. The PEG analogue is a copolymer synthesized by ring-opening alternating copolymerization of succinic anhydride with 2-（（2-（2-metho xyethoxy）ethoxy）methyl）oxirane. The structure of the copolymer was confirmed by ^1H NMR spectrum. The effects of the monomer feed ratio on the copolymerization were studied and the polymerization mechanism was given. The PEG analogue disclosed is water-soluble and expected to have promising applications in biomedical fields as a substitute of PEG due to the existence of degradable ester bond in the backbone.展开更多
基金supported by the National Natural Sciences Fund of China(No.50603025)the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University).
文摘Poly（d,l-lactide-co-p-dioxanone） （P（LA-co-PDO）） copolymers with different chain microstructures were synthesized by onestep or two-step bulk ring-opening polymerizations of d,l-lactide （LA） and p-dioxanone （PDO） monomers using stannous octoate [Sn（Oct）2]/n-dodecanol as the initiating system. The average sequence lengths of the lactidyl （LLA） and dioxanyl （LpDo） units were calculated from the ^1H NMR spectra. It was found that both LLA and Lpoo values from the two-step syntheses were significantly longer than those from the corresponding one-step syntheses, indicating more blocky structure achieved for the twostep copolymers. Corresponding to this difference in microstructure, the two-step copolymers were semi-crystalline, while the one-step copolymers were completely amorphous. In conclusion, the crystallinity of P（LA-co-PDO） copolymers could be adjusted conveniently to meet specific applications by changing the microstructure of the copolymers via different polymerization routes.
基金supported by the National Natural Sciences Fund of China(No.50603025)the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University).
文摘A novel poly（ethylene glycol） （PEG） analogue composed of aliphatic polyester backbone and pendant oligo（ethylene glycol） short chains is reported. The PEG analogue is a copolymer synthesized by ring-opening alternating copolymerization of succinic anhydride with 2-（（2-（2-metho xyethoxy）ethoxy）methyl）oxirane. The structure of the copolymer was confirmed by ^1H NMR spectrum. The effects of the monomer feed ratio on the copolymerization were studied and the polymerization mechanism was given. The PEG analogue disclosed is water-soluble and expected to have promising applications in biomedical fields as a substitute of PEG due to the existence of degradable ester bond in the backbone.
