The Synthesis And Process Optimization Of Diglycidyl Terephthalate

Diglycidyl terephthalate, as one of glycidyl esters, has been widely used in coatings, composite materials and many other areas because of its high reactivity, excellent adhesive properties and resistance to elements.Firstly, DGT was prepared by the two-step synthesis via the esterification and dehydrohalogenation. The optimum conditions of the two reactions were obtained by orthogonal experiments and single factor experiments respectively, both of which were monitored by TLC and HPLC. The yield was around78%and the epoxy value reached0.57. The epoxy value was raised to0.65by extraction and recrystallation from a mixture of toluene and petroleum ether. Then a pilot-scale chemical research was done and the process flow and conditions were confirmed, laying the basis for futural commercial process.Secondly, DGT was prepared by the two-step synthesis via transesterification and epoxidation both of which were monitored by TLC and HPLC. Diallyl terephthalate was synthesized via transesterification, with the yield of89%at optimized conditions given by single factor experiments. After the oxidant screening, MCPBA was chosen to epoxidize diallyl terephthalate because of its short reaction time, high conversion and selectivity, with a total yield of78%.