Crosslink polymerization kinetics of poly（acrylic acid-co-2-acrylamido-2-methylpropane sulfonic acid）,AA/AMPS hydrogels,was investigated by using dilatometry in the presence of sodium persulfate as initiator and N,N...Crosslink polymerization kinetics of poly（acrylic acid-co-2-acrylamido-2-methylpropane sulfonic acid）,AA/AMPS hydrogels,was investigated by using dilatometry in the presence of sodium persulfate as initiator and N,N＇-methylene bis（acrylamide） as crosslinker.It was found that the reaction for the crosslink polymerization of AA/AMPS hydrogels had orders of 0.58,1.14,and 0.86 with respect to the initiator,AMPS,and AA,respectively.From the Arrhenius plots,the activation energy of the crosslink polymerization was found to be about 140 and 89 kJ·mol-1 in the presence and absence of the crosslinker,respectively,in the temperature range from 45 to 65 °C.It was noted that the crosslinker had effects on the reaction order of the initiator and the activation energy due to the formation of cross-linked networks,which was verified by Fourier transfer infrared （FTIR） spectrum.To further confirm the influences of the cross-linked network structure on kinetic parameters of the crosslink polymerization,a mechanism was proposed,which highlights the different termination routes between free radical polymerization and crosslink polymerization.These results suggest that dilatometry provides a convenient tool for crosslink polymeri-zation study,and confirm that the cross-linked networks are formed in the crosslink polymerization.展开更多
Herein,a facile and highly efficient synthetic method to prepare organic photothermal materials with high photo-stability and outstanding photothermal performance is reported.Through direct polymerization of commercia...Herein,a facile and highly efficient synthetic method to prepare organic photothermal materials with high photo-stability and outstanding photothermal performance is reported.Through direct polymerization of commercial aromatic monomers in the presence of anhydrous aluminium chloride and dichloromethane,four kinds of conjugated microporous polymers(CMPs)were obtained.Detailed structural analysis confirmed that the resultant CMPs possessed abundant micropores with an extendedπ-conjugated skeleton.Under near-infrared(NIR)light irradiation(808 nm,1.0 W cm−2),all the CMPs showed fast heating-up behavior with their maximum temperatures higher than 150℃.Moreover,the efficiency of photothermal conversion(η)of the CMPs was found to increase linearly with the increase in the number of conjugated benzene rings within the monomer.Poly-TPE from tetraphenylethylene(TPE)and Poly-TP from o-terphenyl(TP)showed highηvalues of over 47%.Poly-TPE was additionally used as a photothermal filler to remotely and spatially control the shape recovery of thermal-sensitive shape memory polymers(SMPs),while its introduction(1 wt%)had little influence on the thermal and mechanical properties of the polymer matrixes.Owing to their excellent NIR photothermal performance as well as a one-step synthetic preparation,these CMPs may be promising photothermal materials for practical applications.展开更多
基金Supported by the National Natural Science Foundation of China（20176007 20376087）
文摘Crosslink polymerization kinetics of poly（acrylic acid-co-2-acrylamido-2-methylpropane sulfonic acid）,AA/AMPS hydrogels,was investigated by using dilatometry in the presence of sodium persulfate as initiator and N,N＇-methylene bis（acrylamide） as crosslinker.It was found that the reaction for the crosslink polymerization of AA/AMPS hydrogels had orders of 0.58,1.14,and 0.86 with respect to the initiator,AMPS,and AA,respectively.From the Arrhenius plots,the activation energy of the crosslink polymerization was found to be about 140 and 89 kJ·mol-1 in the presence and absence of the crosslinker,respectively,in the temperature range from 45 to 65 °C.It was noted that the crosslinker had effects on the reaction order of the initiator and the activation energy due to the formation of cross-linked networks,which was verified by Fourier transfer infrared （FTIR） spectrum.To further confirm the influences of the cross-linked network structure on kinetic parameters of the crosslink polymerization,a mechanism was proposed,which highlights the different termination routes between free radical polymerization and crosslink polymerization.These results suggest that dilatometry provides a convenient tool for crosslink polymeri-zation study,and confirm that the cross-linked networks are formed in the crosslink polymerization.
基金the National Natural Science Foundation of China(51503231 and 21374136)Guangdong Innovative and Entrepreneurial Research Team Program(2013S086)the Fundamental Research Funds for the Central Universities(17lgjc03 and 18lgpy04)。
文摘Herein,a facile and highly efficient synthetic method to prepare organic photothermal materials with high photo-stability and outstanding photothermal performance is reported.Through direct polymerization of commercial aromatic monomers in the presence of anhydrous aluminium chloride and dichloromethane,four kinds of conjugated microporous polymers(CMPs)were obtained.Detailed structural analysis confirmed that the resultant CMPs possessed abundant micropores with an extendedπ-conjugated skeleton.Under near-infrared(NIR)light irradiation(808 nm,1.0 W cm−2),all the CMPs showed fast heating-up behavior with their maximum temperatures higher than 150℃.Moreover,the efficiency of photothermal conversion(η)of the CMPs was found to increase linearly with the increase in the number of conjugated benzene rings within the monomer.Poly-TPE from tetraphenylethylene(TPE)and Poly-TP from o-terphenyl(TP)showed highηvalues of over 47%.Poly-TPE was additionally used as a photothermal filler to remotely and spatially control the shape recovery of thermal-sensitive shape memory polymers(SMPs),while its introduction(1 wt%)had little influence on the thermal and mechanical properties of the polymer matrixes.Owing to their excellent NIR photothermal performance as well as a one-step synthetic preparation,these CMPs may be promising photothermal materials for practical applications.
