Study on the curing process and thermal property of poly (ethyleneglycol)-based amino-terminated polyurethanes/epoxy resin

Abstract

Poly (ethylene glycol)-based amino-terminated polyurethane (ATPU) is a novel kind of flexible curing agent of epoxy resin, containing both flexible chains and rigid groups. This novel curing agent can increase the strength and toughness of epoxy resin. The dissertation mainly studied the curing processing characteristics, curing reaction mechanism and curing reaction kinetic of ATPU/E-44 adhesive, while the thermal decomposition kinetics and the dynamic mechanical behavior of cured adhesive were also studied. In this paper, Based on the synthesis of the novel curing agent ATPU the influence of the type and the amount of curing agent ATPU on the curing reaction processing and curing reaction kinetic were studied by DSC method. The results showed that the amount of ATPU curing agent have an obvious influence on the curing reaction heat and curing degree. With increasing the amount of the curing agent ATPU, the curing reaction heat and curing degree increases. The curing reaction active energy of the ATPU-2/E-44 adhesive is lower than that of ATPU-1.5/E-44 adhesive, which indicates that the curing agent ATPU-2 have better curing reactivity. The FTIR spectra were used to characteristic the cured epoxy resin. The results showed that the curing time and curing temperature have great effects on the curing processing and curing reaction mechanism; the higher curing temperature would increase the curing degree. The TG-DTA results showed that the decomposition temperature of the cured adhesive of ATPU-2/E-44 system is higher than that of the cured adhesive of ATPU-1.5/E-44 system, which indicates that the cured adhesive of ATPU-2/E-44 system have better heat resistance. The DMA study showed that the cured adhesive of ATPU-2/E-44 system has higher glass transition temperature and dynamic modulus.

Alternate abstract:

端胺基聚氨酯（ATPU）是一种新型的环氧树脂固化剂，它含有刚性单元和柔性链，能同时增强、增韧环氧树脂；本文主要研究这种ATPU/环氧树脂胶粘剂固化反应过程特点及固化反应机理，阐明固化过程动力学特征和影响固化过程动力学的因素，以优化固化工艺条件。研究了ATPU/EP胶粘剂固化物的热稳定性特征和热失效机理，以及动态力学行为。 在合成固化剂ATPU的基础上，采用差示扫描量热法（DSC）研究了固化剂ATPU种类和用量对环氧树脂固化反应过程的影响规律，分析了 ATPU/E-44胶粘剂固化反应动力学特征。结果表明，ATPU的含量对固化放热特征，放热量和固化程度等有显著的影响。随着固化剂用量的增加，固化放热量和固化度均增加；与固化剂ATPU-1.5比较，固化剂ATPU-2具有较好的反应活性，其固化反应活化能低于ATPU-1.5体系。 采用热分析仪与傅立叶红外光谱仪（FTIR）等测试手段，研究了固化温度、固化时间对固化物的组成与结构的影响规律，分析了固化过程化学反应机理。得到了最佳固化工艺是ATPU-2/E-44体系室温固化1周。 采用综合热分析仪研究了ATPU/环氧树脂胶粘剂固化物的热稳定性特征和热分解动力学。结果表明，ATPU-2/E44固化物具有更好的热稳定性。采用动态热机械分析仪（DMA）研究了ATPU/环氧树脂胶粘剂固化物的动态热机械特性,发现ATPU-2具有更好的增韧改性作用，固化后可以获得更高的玻璃化转变温度和较高的动态弹性模量。