低熔点聚酰胺的合成与应用研究进展

Research progress in synthesis and application of low-melting point polyamide

综述了近年来低熔点聚酰胺(PA)的合成方法及其下游应用的研究进展。在PA中掺入无机金属盐共混后,金属盐的金属离子可与PA的酰胺基团产生络合作用,降低其结晶度和熔点。不同结构单元的尼龙盐混合后进行熔融或溶液缩聚;多种二元酸与多种二元胺直接进行熔融聚合;以二聚酸替代二元酸与二元胺或多元胺直接进行熔融聚合是目前工业生产低熔点PA最常用的方法。己内酰胺与聚醚、聚酯、聚醇等通过多步法活性阴离子聚合或者水解开环聚合可制备低熔点PA,但熔点下降有限。低熔点PA主要应用于热熔胶、热粘合纤维以及工程塑料等领域,与国外产品相比,国内低熔点PA产品的品种、质量及应用仍有较大差距,研究和探索低熔点PA的合成工艺及其下游应用具有重要的现实意义和经济价值。

The research progress in the synthesis techniques and down-stream application of low-melting point polyamide （PA） was reviewed in the latest years. The incorporation of inorganic metal salt could decrease the crystallinity and melting point of PA due to the complex reaction between metal ions and amide group. Nylon salt with different structural units was blended prior to melting or solution polycondensation. Versatile diacids and diamines were directly exposed to melt polymerization. The conven- tional commercial production technique of low-melting point PA was the melt polymerization between diamine or muhi-amide and dimer acid as a substitute for diacid. Low-melting point PA could be produced with a limited decrease of melting point by multi- stage active anion polymerization or hydrolysis ring-opening polymerization between caprolactam and polyether, polyester and polyols. Low-melting point PA was mainly applied in the fields of hot melt adhesives, heat bonded fiber and engineering plastics. There is great difference between China-made and overseas low-melting point polyamide in variety quality and application. The research of the synthesis techniques and down-stream application of low-melting point PA had a practical significance and econom- ic value.