A simple one-pot non-isocyanate route for synthesizing thermoplastic polyureas is presented. In situ urethanization was conducted from the ring-opening reaction of ethylene carbonate with poly(propylene glycol) bis(2-...A simple one-pot non-isocyanate route for synthesizing thermoplastic polyureas is presented. In situ urethanization was conducted from the ring-opening reaction of ethylene carbonate with poly(propylene glycol) bis(2-aminopropyl ether) and hexanediamine,m-xylylenediamine, or diethylene glycol bis(3-aminopropyl) ether at 100 °C for 6 h under normal pressure. Melt transurethane polycondensation was successively conducted at 170 °C under a reduced pressure of 399 Pa for different time periods. A series of nonisocyanate thermoplastic polyureas(NI-TPUreas) were prepared. The NI-TPUreas were characterized by gel permeation chromatography,FTIR, 1 H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray diffraction, atomic force microscopy,and tensile test. NI-TPUreas exhibited Mn of up to 1.67 × 104 g/mol, initial decomposition temperature over 290 °C, and tensile strength of up to 32 MPa. Several crystallizable NI-TPUreas exhibited Tm exceeding 98 °C. NI-TPUreas with good thermal and mechanical properties were prepared through a green and simple one-pot non-isocyanate route.展开更多
A simple non-isocyanate route is developed for synthesizing crystallizable aliphatic thermoplastic poly（ester urethane） elastomers （TPEURs） with good thermal and mechanical properties. Three prepolymers of 1,6-bis...A simple non-isocyanate route is developed for synthesizing crystallizable aliphatic thermoplastic poly（ester urethane） elastomers （TPEURs） with good thermal and mechanical properties. Three prepolymers of 1,6-bis（hydroxyethyloxycarbonylamino） hexane （BHCH）, i.e. PrePBHCHs, were prepared through the self-transurethane polycondensation of BHCH. A poly（butylene adipate） prepolymer （PrePBA） with terminal HO-- groups was prepared and used as a polyester glycol. A series of TPEURs were prepared by the co-polycondensation of the PrePBHCHs with PrePBA at 170 ℃under a reduced pressure of 399 Pa. The TPEURs were characterized by gel permeation chromatography, FTIR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray diffraction, atomic force microscopy, and tensile test. The TPEURs exhibited Mn up to 23300 g/mol, Mw up to 51100 g/mol, Tg ranging from -33.8 ℃ to -3.1 ℃, Tm from 94.3 ℃ to 111.9 ℃, initial decomposition temperature over 274.7℃, tensile strength up to18.8 MPa with a strain at break of 450.0%, and resilience up to 77.5%. TPU elastomers with good crystallization and mechanical properties were obtained through a non-isocyanate route.展开更多
A simple non-isocyanate route synthesizing thermoplastic polyurethanes（TPUs） with good thermal and mechanical properties is described. Melt transurethane polycondensation of dimethyl 1,6-hexamethylene dicarbamate wi...A simple non-isocyanate route synthesizing thermoplastic polyurethanes（TPUs） with good thermal and mechanical properties is described. Melt transurethane polycondensation of dimethyl 1,6-hexamethylene dicarbamate with 1,4-butanediol and 1,6-hexanediol was conducted at different molar ratios under the catalysis of tetrabutyl titanate. A series of crystallizable non-isocyanate TPUs with high molecular weight were prepared. The TPUs were characterized by gel permeation chromatography, FT-IR, 1 H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X-ray diffraction, AFM, and tensile tests. The TPUs exhibited Mn ranging from 12 500 to 26 400 g/mol, Mw from 16 700 to 56 400 g/mol, Tm up to 151.4 °C, and initial decomposition temperature over 241.8 °C. Their tensile strength reached 42.99 MPa with a strain at break of 30.00%. TPUs constructed simply with butylene, hexylene, and urethane linkages were successfully synthesized through a non-isocyanate route.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 21244006)Beijing Natural Science Foundation (No. 2182056)
文摘A simple one-pot non-isocyanate route for synthesizing thermoplastic polyureas is presented. In situ urethanization was conducted from the ring-opening reaction of ethylene carbonate with poly(propylene glycol) bis(2-aminopropyl ether) and hexanediamine,m-xylylenediamine, or diethylene glycol bis(3-aminopropyl) ether at 100 °C for 6 h under normal pressure. Melt transurethane polycondensation was successively conducted at 170 °C under a reduced pressure of 399 Pa for different time periods. A series of nonisocyanate thermoplastic polyureas(NI-TPUreas) were prepared. The NI-TPUreas were characterized by gel permeation chromatography,FTIR, 1 H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray diffraction, atomic force microscopy,and tensile test. NI-TPUreas exhibited Mn of up to 1.67 × 104 g/mol, initial decomposition temperature over 290 °C, and tensile strength of up to 32 MPa. Several crystallizable NI-TPUreas exhibited Tm exceeding 98 °C. NI-TPUreas with good thermal and mechanical properties were prepared through a green and simple one-pot non-isocyanate route.
基金financially supported by the National Natural Science Foundation of China(Nos.21244006 and 50873013)
文摘A simple non-isocyanate route is developed for synthesizing crystallizable aliphatic thermoplastic poly（ester urethane） elastomers （TPEURs） with good thermal and mechanical properties. Three prepolymers of 1,6-bis（hydroxyethyloxycarbonylamino） hexane （BHCH）, i.e. PrePBHCHs, were prepared through the self-transurethane polycondensation of BHCH. A poly（butylene adipate） prepolymer （PrePBA） with terminal HO-- groups was prepared and used as a polyester glycol. A series of TPEURs were prepared by the co-polycondensation of the PrePBHCHs with PrePBA at 170 ℃under a reduced pressure of 399 Pa. The TPEURs were characterized by gel permeation chromatography, FTIR, 1H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide-angle X-ray diffraction, atomic force microscopy, and tensile test. The TPEURs exhibited Mn up to 23300 g/mol, Mw up to 51100 g/mol, Tg ranging from -33.8 ℃ to -3.1 ℃, Tm from 94.3 ℃ to 111.9 ℃, initial decomposition temperature over 274.7℃, tensile strength up to18.8 MPa with a strain at break of 450.0%, and resilience up to 77.5%. TPU elastomers with good crystallization and mechanical properties were obtained through a non-isocyanate route.
基金Funded by the National Natural Science Foundation of China(Nos.21244006 and 50873013)the Beijing Natural Science Foundation(No.2182056)
文摘A simple non-isocyanate route synthesizing thermoplastic polyurethanes（TPUs） with good thermal and mechanical properties is described. Melt transurethane polycondensation of dimethyl 1,6-hexamethylene dicarbamate with 1,4-butanediol and 1,6-hexanediol was conducted at different molar ratios under the catalysis of tetrabutyl titanate. A series of crystallizable non-isocyanate TPUs with high molecular weight were prepared. The TPUs were characterized by gel permeation chromatography, FT-IR, 1 H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X-ray diffraction, AFM, and tensile tests. The TPUs exhibited Mn ranging from 12 500 to 26 400 g/mol, Mw from 16 700 to 56 400 g/mol, Tm up to 151.4 °C, and initial decomposition temperature over 241.8 °C. Their tensile strength reached 42.99 MPa with a strain at break of 30.00%. TPUs constructed simply with butylene, hexylene, and urethane linkages were successfully synthesized through a non-isocyanate route.
