The Synthesis Of Polyamide Acid Oligomer And The Sdudy Of Epoxy Resin Modified With It

Epoxy resin has many excellent properties which plays a great role in industry, machinery, electron and so on. However, there are many shortages (poor toughness, poor weather fastness, poor impact strength, etc.) limiting the application of epoxy resins. So this article uses ether dianhydride and ether diamine to synthesize polyamide acid oligomer (PAA-n), as a reactive modifier to modify epoxy resin, meanwhile to study the performance of the modified epoxy resin.The product has been characterized by infrared spectrum (FTIR), nuclear magnetic resonance (NMR) H spectrum, Differential Scanning Calorimetry(DSC)and electro spray mass spectrometry(ESI), and then study its chemical reactivity and compatibility with epoxy resin. The thermal and mechanical properties of modified epoxy resin have also been studied with PAA-n as reactive modifier of epoxy resin.Research results show that:FTIR and NMR show that PAA-n contains reactive groups such as amino, carboxyl and amide group, DSC measured its melting point is159℃, ESI measured the relative molecular mass is710. The research indicates that PAA-n and epoxy resin have good reactivity and compatibility. It contains amino, aromatic carboxylic and amide group, which can participate in the curing reaction of epoxy resin to form a three-dimensional cross-linked network structure. PAA-n as a reactive modifier can modify DDS/128epoxy resin system. Under the proper ratio and curing mechanism, PAA-n modified epoxy can reach to good mechanical performance and the same time thermal performance can be improved。...