Synthesis and characterization of oxazolidones with improved thermal stability

To increase thermal stability for high performance applications of epoxy resin system – Diglycidal Ether of bisphenol-A (DGEBA), the epoxy backbone is modified to incorporate aromatic and heterocyclic rings i.e. the oxazolidone ring. FTIR studies were conducted during the synthesis at various intervals. Appearance of peak at 1754 cm confirms the presence of oxazolidone ring and absence of peak at 915 cm and 1730 cm in the reaction mixture confirms complete consumption of epoxy groups and absence of trimeric isocyanate in the modified resin. Study of char yield during TGA studies indicates that as compared to 5% char yield in unmodified resin, the char yield in oxazolidone modified resin is 25–28%, thus confirming the higher thermal stability of modified epoxy resin. The present work indicates that thermal stability of modified epoxy increased in the range of 27.9% 35.5%. The activation energy E and order of reaction (n) was calculated by Coats and Redfern equation. Overall value of E lies in the range 41.8 – 118.3 KJ mol.