高分子量二元丙烯腈聚合物的合成及性能

设计合成了双功能共聚单体3-酰胺基-3-丁烯酸甲酯(MMPA),以二元共聚合代替传统的三元共聚合,采用水相悬浮聚合的方法制备超高分子量丙烯腈二元共聚物作为碳纤维前驱体。采用傅里叶红外变换光谱仪、差示扫描量热分析仪和热失重分析仪详细研究了单体配比对聚合物相对分子质量、结构及预氧化性能的影响,结果表明,共聚单体MMPA的加入使预氧化温度由240℃降低至213℃,且投料中随着MMPA含量的增加预氧化温度降低,预氧化程度加深,合成的共聚单体MMPA能够有效改善丙烯腈聚合物的预氧化性能,宽化放热峰,避免放热集中;水相悬浮制备得到的丙烯腈聚合物相对分子质量高达106.7×10~4,有利于提高碳纤维的力学性能。

Preparation and Properties of High Molecular Weight Acrylonitrile Copolymer

A bifunctional comonomer3-methoxycarbonylate-2-methylenpropanamide (MMPA) was synthesized to prepare poly (acrylonitrile-co-3-methoxycarbonylate-2-methylenpropanamide) P (AN-co-MMPA)] by aqueous suspension polymerization,which was used as carbon fiber precursor instead of acrylonitrile terpolymers.The effect of the monomer feed ratio on the molecular weight,structure and stabilization of P(AN-co-MMPA) was studied by Fourier transform infrared spectroscopy,thermogravimetry and differential scanning calorimetry in detail.The results show that the initiation temperature is reduced from 240 ℃ to 213 ℃,and the extent of stabilization of P(AN-co-MMPA) increases with increasing of the MMPA content in the feed.It can be concluded that the stabilization of P (AN-co-MMPA) is effectively improved by the bifunctional MMPA with lower initiation temperature and broaden exothermic peak,which can avoid centralized heat release;the molecular weight of P(AN-cO-MMPA) prepared by aqueous suspension polymerization is as high as 1.06 × 106,which is beneficial to improve the mechanical properties significantly.