【摘要】 采用核磁共振氢谱（¹H-NMR）对经4,4’-二氨基二苯砜（4,4’-DDS）改性后的聚对苯二甲酰间苯二胺（co-PMTA₃）进行化学结构表征;研究了co-PMTA₃的溶解性和热性能,并与对位聚芳砜酰胺（p-PSA）和常规聚芳砜酰胺（co-PSA）进行了比较;采用湿法纺丝方法制得了co-PMTA₃初生纤维,将初生纤维经340℃热拉伸1.4倍后制得线密度为10 dtex的co-PMTA₃纤维,研究了co-PMTA₃纤维的力学性能。结果表明:coPMTA₃为4,4’-DDS与间苯二胺及对苯二甲酰氯按其摩尔比为2.5/7.5/10的共聚物;co-PMTA₃的溶解性强于pPAS,但比co-PSA要弱;co-PMTA₃有较好的耐热性,其玻璃化转变温度达318.4℃,低于p-PSA的367.7℃和coPSA的343.1℃;co-PMTA₃纤维的断裂强度为4.7 cN/dtex,初始模量为56.5 cN/dtex,打结强度为2.2 cN/dtex。更多还原

【Abstract】 A modified poly-m-phenylene terephthalamide（co-PMTA₃） soluble in DMAc was prepared by incorporating with4,4’-diamino diphenyl sulfone（4,4’-DDS） in backbone and then was spun into fiber via wet spinning.The chemical structure and constitution of co-PMTA₃ was characterized by ¹H-nuclear magnetic resonance spectrometry（¹H-NMR）.The solubility of co-PMTA₃ was investigated by cloud point titration method（CPM） in ternary phase（co-PMTA₃/DMAc/H₂O）.The thermal property of co-PMTA₃ was investigated by differential scanning calorimetry（DSC） and was compared with those of all paraposition polysulfonamide（p-PSA） and normal polysulfonamide（co-PSA）.The as-spun co-PMTA₃ fiber was drawn at 340 ℃to a ratio of 1.4,and the hot-drawn co-PMTA₃ fiber with 10 dtex in the linear density was obtained.The mechanical properties of co-PMTA₃ were studied.The results indicated that co-PMTA₃ was the polymer of 4,4’-DDS/m-phenylenediamine/terephthaloyl dichloride at the mole ratio of 2.5/7.5/10; the co-PMTA₃ possessed excellent heat resistance with a glass-transition temperature of 318.4 ℃ which was lower than those of p-PSA（367.7 ℃） and co-PSA（343.1 ℃）; the co-PMTA₃ fiber had high mechanical properties with a breaking strength of 4.7 cN/dtex,an initial modulus of 56.5 cN/dtex and a knot tenacity of2.2 cN/dtex,respectively.更多还原