A pH-sensitive modified polyacrylamide hydrogel was prepared by two steps and the modified polyacrylamide was characterized by ^1HNMR spectrum. The surface morphology and swelling behavior of the hydrogels were invest...A pH-sensitive modified polyacrylamide hydrogel was prepared by two steps and the modified polyacrylamide was characterized by ^1HNMR spectrum. The surface morphology and swelling behavior of the hydrogels were investigated.展开更多
In order to explore new substitutes for 2,5 furandicarboxylic acid(FDCA)or poly(ethylene 2,5 furandicarboxylate)(PEF)and try to develop more ideal bio based polyesters,several thiophene aromatic polyesters(PETH,PPTH,P...In order to explore new substitutes for 2,5 furandicarboxylic acid(FDCA)or poly(ethylene 2,5 furandicarboxylate)(PEF)and try to develop more ideal bio based polyesters,several thiophene aromatic polyesters(PETH,PPTH,PBTH,and PHTH)were synthesized from dimethyl thiophene 2,5-dicarboxylate(DMTD)and different diols,including ethylene glycol,1,3-propanediol,1,4-butanediol,and 1,6-hexanediol.The chemical structures of obtained polyesters were confirmed by nuclear magnetic resonance spectroscopy(H-NMR and 1'C-NMR).Determined by GPC measurement,their average molecular weight(M.)varied from 5.22 x 10*g/mol to 7.94 x 10*g/mol with the molar-mass dispersity of 1.50-2.00.Based on the DSC and TGA results,the synthesized polyesters PETH,PPTH,and PBTH displayed comparable or even better thermal properties when compared with their FDCA-based analogues.From PETH to PHTH,their Tg varied from 64.6°Cto-1°C while Tsm ranged from 409 C to 380°C in nitrogen atmosphere,PETH showed elongation at break as high as 378%,tensile strength of 67 MPa,and tensile modulus of 1800 MPa.Meanwhile,the CO2 and O2 barrier of PETH was 12.0 and 6.6 folds higher than those of PET,respectively,and similar to those of PEF.Considering the overall properties,the synthesized thiophene aromatic polyesters,especially PETH,showed great potential to be used as an excellent bio based packaging material in the future.展开更多
文摘A pH-sensitive modified polyacrylamide hydrogel was prepared by two steps and the modified polyacrylamide was characterized by ^1HNMR spectrum. The surface morphology and swelling behavior of the hydrogels were investigated.
基金This work was finanially supported by the National Natural Science Foundation of China(No.21975270)Zhejiang Provincial Natural Science Foundation of China(No.LR20E030001)+2 种基金Ningbo 2025 Key Scientific Research Programs(No.2018810015)National Key Research and Development Program of China(No.2018YFD0400700)Research Project of Ningbo Natural Science Foundation(No.2019A610141).
文摘In order to explore new substitutes for 2,5 furandicarboxylic acid(FDCA)or poly(ethylene 2,5 furandicarboxylate)(PEF)and try to develop more ideal bio based polyesters,several thiophene aromatic polyesters(PETH,PPTH,PBTH,and PHTH)were synthesized from dimethyl thiophene 2,5-dicarboxylate(DMTD)and different diols,including ethylene glycol,1,3-propanediol,1,4-butanediol,and 1,6-hexanediol.The chemical structures of obtained polyesters were confirmed by nuclear magnetic resonance spectroscopy(H-NMR and 1'C-NMR).Determined by GPC measurement,their average molecular weight(M.)varied from 5.22 x 10*g/mol to 7.94 x 10*g/mol with the molar-mass dispersity of 1.50-2.00.Based on the DSC and TGA results,the synthesized polyesters PETH,PPTH,and PBTH displayed comparable or even better thermal properties when compared with their FDCA-based analogues.From PETH to PHTH,their Tg varied from 64.6°Cto-1°C while Tsm ranged from 409 C to 380°C in nitrogen atmosphere,PETH showed elongation at break as high as 378%,tensile strength of 67 MPa,and tensile modulus of 1800 MPa.Meanwhile,the CO2 and O2 barrier of PETH was 12.0 and 6.6 folds higher than those of PET,respectively,and similar to those of PEF.Considering the overall properties,the synthesized thiophene aromatic polyesters,especially PETH,showed great potential to be used as an excellent bio based packaging material in the future.
