Preparation, liquid crystal property and thermodynamic property of Amine-terminated polyesterimide, as modifiers for epoxy resin

Epoxy resin is widely used in electronic packaging. However, neat epoxy resin is no suitable for high-performance applications because of its poor thermal stability and toughness. Polyimide is a kind of materials with high performance for their excellent thermal stability, dimensional stability and electric property, but it is generally insoluble and infusible, and this makes it difficult to process. In this study, Amine-terminated polyesterimide (ATPEI) polymers was synthesized and used as modifier of epoxy resin. The chemical structure of ATPEI was characterized by FT-IR spectrum. The two melting peaks of differential scanning calorimetry (DSC) show ATPEI manifested liquid crystal properties, which could be verified by Polarizing microscope (POM) and X-ray diffraction (XRD) respectively. ATPEI was used to improve the thermostability, mechanical properties and especially the toughness of bisphenol A diglycidyl ether epoxy resin(ER) cured with 4,4'-Methylenedianiline (DDM). The results show that the decomposition temperature of modified materials improve about 30°C compared with that of unmodified epoxy resin. The mechanical and dynamic mechanical properties were measured by universal testing machine and DMA. The results exhibit that ATPEI modified epoxy resin has good toughness.