投料方式对丙烯腈-丙烯酸甲酯共聚物和纤维熔融行为的影响

Influence of batch feeding mode on the melt processability of acrylonitrile-methly acrylate copolymer and fiber

采用水相沉淀聚合法分批次添加原料制备投料比为85/15（摩尔百分数,下同）的丙烯腈-丙烯酸甲酯共聚物（85/15AN/MA）,研究单体投料方式对共聚物组成、黏度、数均序列长度以及可熔融行为的影响;在190-210℃下采用熔融纺丝工艺制备了AN/MA初生纤维。采用红外光谱（FT-IR）、核磁共振波谱（NMR）、差热分析（DSC）、扫描电子显微镜（SEM）和纤维强力仪等对聚合产物和纤维进行了表征分析。结果表明：随着单体投料方式由一次性添加改变至匀速滴加,共聚物的组成与投料比接近,特性黏度由0.88dL/g降低至0.31dL/g,玻璃化转变温度（Tg）由87.6℃降低至83.8℃,熔融温度由140℃降低至138℃,AN单元的数均序列长度由10.53降低至8.00。聚合过程中分3次投料制备的初生纤维表面光滑,横截面致密,断裂强度为2.4cN/dtex,进行后拉伸等处理后,可满足服用要求。

A series of acrylonitrile-methyl acrylate copolymers with a constant feed molar ratio of 85/15（85/15AN/MA）were synthesized by aqueous redox initiated polymerization.Identification of suitable feeding mode and achieving the optimum melt processability of the copolymer were the main objectives of this investigation.The PAN-based fiber could be formed by melt spinning used the melt spinnable 85/15AN/MA at 190-210℃.The results showed that the tacticity was atactic 53% m and 47% r diads.The glass transition temperatures（Tg）was in the range of 83.8-87.6℃.The lowest melting temperature was 140℃,and the highest decomposition temperature（Td）was 320℃.The intrinsic viscosities were in the range of 0.30-0.88dL/g,which were affected by feeding ways.The tensile strengths of as-spun fibers were in the range of 1.2-2.4cN/dtex.