Synthesis And Characterization Of Novel Self-Curing Epoxy Tesin

Epoxy compounds containing a unique epoxy group, polar hydroxyl and ether active groups, which has many excellent properties, It is widely used in different fields(machinery, electronics, aeronautics, coating). Compared to other type epoxy resin, terephthalic acid glycidyl type epoxy resin possess low viscosity, good manufacturability, great reactivity, good miscibility with phenolic resin and other epoxy resin; bonding strength,electrical insulation et.al. So far there have been some studies on synthesis of terephthalic acid glycidyl type epoxy resin via terphthalic acid followed by epoxidation with epichlorohydrin. The main work of the dissertation was as following:1. The thesis was different of previous studies, self-regulating monomer 2,5-dihydroxy terephthalic acid(DHTA) structure introducing phenolic hydroxyl compared to terephthalic acid, as a characteristic point of synthesis of self-curing epoxy resin. Synthesis of DHTA used dimethyl succinic succinate(DMSS) as a raw material. The chemical structure and microcosmic morphology of DHTA was characterized by FTIR, 1H-NMR,13C-NMR, POM analyses, experimental results showed that the target product prepared was monomer DHTA.2. However, so far there have been no reports on self-curing epoxy based on the glycidyl ester type epoxy resin which is seemed as the innovation, this dissertation used dicarboxylic acid-epichlorohydrin two-step method,successfully designed and prepared a novel glycidy ester type epoxy resin with 2,5-dihydroxy terephthalic acid(DHTA) followed by epoxidation with excess epichlorohydrin in alkaline catalyst conditions. Molecular weight and molecular weight distribution of SC-ER was characterized by GPC analyses, the results showed that synthesized products SC-ER mianly consested of tetramers and dimers, and the amount of dimers were higher than tetramers, tetramers possess wider molecular weight distribution. Fourier transform infrared spectroscopy analysis showed that the product structure of SC-ER containing epoxy groups, carboxyl occurred esterification, phenolic hydroxyl in the process of synthesis of SC-ER did not react, these confirmed the SC-ER structure coincided with expected theoretical structure. The nonisothermal curing reaction kinetics of SC-ER was characterized with DSC with dynamic modes, The apparent activation energy of curing reaction were determined by the Kissinger and Ozawa methods, and determined the best curing process conditions. FTIR analyses indicated that SC-ER without adding curing agent could occurred self-curing reaction, during the curing process, reaction of epoxy groups with phenolic hydroxyl groups generated the cured product with the aromatic ether structure, and discussed possible self-curing reaction mechanism.