Effect Of Triphenylphosphine On The Cure Reaction and Thermal Stability Of Diglycidyl Ether Of bisphenol A-based Epoxy Resin

摘要

Asulphone-nitrogen containing heterocyclic ring, tetraphenylthiophene diamine (TPTDA) was prepared and used as curing agent together with triphenylphosphine (PPh_3) to cure diglycidyl ether of a bisphenol A-based epoxy resin (DGEBA). Activation energies (E_a) for curing DGEBA/TPTDA and DGEBA/ TPTDA/PPh_3 systems by using DSC data and Kissinger equation are 66.6 kJ/mol and 76.6 kJ/mol, respectively. The increase in E_a can be due to polymerization of DGEBA by PPh_3 and formation of larger molecules with reduced mobility before curing with TPTDA to start. E_a of thermal degradation of cured DGEBA/TPTDA and DGEBA/TPTDA/PPh_3 systems by using TGA data and Horowitz-Metzger equation are 56.0 kJ/mol and 128.0 kJ/mol, respectively. The onset decomposition temperature and the char yield have increased from 230℃ to 320℃ and from 21.4% to 32.5% for the above systems, respectively. The addition of PPh_3 to the curing mixture enhanced char formation and improved thermal stability of the resin.