熔融共混加工过程中的酰胺交换反应

Transamidation of Polyamide Melt Blending Process

聚酰胺(Polyamide, PA)是应用最广的工程塑料之一。不同类型聚酰胺的加工及耐热吸湿等诸多性能存在较大差异,为进一步改善聚酰胺材料的综合性能并降低成本,熔融共混是最基本的方法。熔融共混时受高温和机械力场的影响,酰胺键打开重新排列发生交换反应,均聚物转化为共聚物,导致高分子链结构、结晶结构和更高层次的聚集态结构发生变化,材料强度、模量、韧性、热变形、吸湿等性能发生变化,从而满足特定应用场景需求。本文对熔融共混加工过程酰胺交换反应的研究进行归纳总结,介绍了酰胺交换反应的分析表征手段、具体的研究体系以及促进和抑制交换反应的方法。此外,对聚酰胺与聚酯、聚氨酯等其他高分子材料的交换反应也简要对比讨论。最后对利用酰胺交换反应及动态化学原理设计和制备高分子材料进行展望分析。

Polyamide(PA)is one of the most widely used engineering-plastics.Different typs of PAs have distinct variations in properties,such as processability,heat-resistance and water adsorption.In order to further improve the comprehensive performance of polyamide materials and reduce costs,melt blending is the most basic method.Under the influence of high temperature and mechanical force field during melt blending,the amide bond is opened and rearranged to undergo an exchange reaction,and the homopolymer is first converted into a copolymer,resulting in changes in the polymer chain structure,crystalline structure and higher-level aggregation structure.The strength,modulus,toughness,thermal deformation,moisture absorption and other properties of the material change to meet the needs of specific application scenarios.This paper summarizes the transamidation of PA blending,including characterization techniques,the available research systems,accelerating,and restriction process.The transamidation of polyamide with other polymers,such as polyester and polyurethane is also briefly discussed.Finally,the design and preparation of polymer materials based on transamidation and dynamic chemistry principle are prospected.