Terpolymers of N-p-tolylmaleimide(NPTMI), methyl methacrylate(MMA) and acrylonitrile(AN) were synthesized by emulsion polymerization. The thermal properties of the terpolymers were investigated by torsional braid anal...Terpolymers of N-p-tolylmaleimide(NPTMI), methyl methacrylate(MMA) and acrylonitrile(AN) were synthesized by emulsion polymerization. The thermal properties of the terpolymers were investigated by torsional braid analysis, differential scanning calorimetry, thermogravimetric analysis and vicat softening point tester. The results showed that the glass transition temperature(T g) and vicat softening point of the terpolymers increased with the increase of NPTMI content but decreased with the increase of AN content. The initial decomposition temperature(T 0) and the half weight-loss temperature(T 50 ) increased both with increasing NPTMI and AN content. The weight and number average molecular weights were also determined by gel permeation chromatography. The results showed that there was a maximum value at mass ratio 10∶85∶5 of NPTMI/MMA/AN.展开更多
Four armed star shaped copolymer of methyl methacrylate(MMA)/ N cyclohexylmaleimide(NCMI) with heat resistance was synthesized by atom transfer radical copolymerization with the CuBr/bpy catalyst in anisole, initiated...Four armed star shaped copolymer of methyl methacrylate(MMA)/ N cyclohexylmaleimide(NCMI) with heat resistance was synthesized by atom transfer radical copolymerization with the CuBr/bpy catalyst in anisole, initiated by tetra(bromomethyl)benzene. A linear plot of ln( 0/) versus reaction time was obtained by using anisole as solvent. In contrast, the use of cyclohexanone as solvent results in that the rate of copolymerization decreases as the reaction proceeds. Using anisole as the solvent in the copolymerization, the molecular weight of the resultant copolymer(measured by triple detection SEC) increased linearly with the increase of conversion, and the molecular weight distributions are narrow. The glass transition temperature of the resultant copolymer was higher than that of the pure PMMA. The synthesized four armed star copolymer was used as macroinitiator for the cationic polymerization of 2 methyl 2 oxazoline to yield star shaped poly(MMA co NCMI)/poly(2 methyl 2 oxazoline) block copolymers. The approximately linear increase of the molecular weight with the increase of reaction time and the low molecular weight distribution demonstrate a controlled chain extension reaction.展开更多
文摘Terpolymers of N-p-tolylmaleimide(NPTMI), methyl methacrylate(MMA) and acrylonitrile(AN) were synthesized by emulsion polymerization. The thermal properties of the terpolymers were investigated by torsional braid analysis, differential scanning calorimetry, thermogravimetric analysis and vicat softening point tester. The results showed that the glass transition temperature(T g) and vicat softening point of the terpolymers increased with the increase of NPTMI content but decreased with the increase of AN content. The initial decomposition temperature(T 0) and the half weight-loss temperature(T 50 ) increased both with increasing NPTMI and AN content. The weight and number average molecular weights were also determined by gel permeation chromatography. The results showed that there was a maximum value at mass ratio 10∶85∶5 of NPTMI/MMA/AN.
文摘Four armed star shaped copolymer of methyl methacrylate(MMA)/ N cyclohexylmaleimide(NCMI) with heat resistance was synthesized by atom transfer radical copolymerization with the CuBr/bpy catalyst in anisole, initiated by tetra(bromomethyl)benzene. A linear plot of ln( 0/) versus reaction time was obtained by using anisole as solvent. In contrast, the use of cyclohexanone as solvent results in that the rate of copolymerization decreases as the reaction proceeds. Using anisole as the solvent in the copolymerization, the molecular weight of the resultant copolymer(measured by triple detection SEC) increased linearly with the increase of conversion, and the molecular weight distributions are narrow. The glass transition temperature of the resultant copolymer was higher than that of the pure PMMA. The synthesized four armed star copolymer was used as macroinitiator for the cationic polymerization of 2 methyl 2 oxazoline to yield star shaped poly(MMA co NCMI)/poly(2 methyl 2 oxazoline) block copolymers. The approximately linear increase of the molecular weight with the increase of reaction time and the low molecular weight distribution demonstrate a controlled chain extension reaction.
