ABOUT THE THERMAL DEGRADATION OF SOME SEMI-INTERPENETRATING POLYMER NETWORKS BASED ON POLYURETHANE AND EPOXY MALEATE OF BISPHENOL A

摘要

The thermal degradation of two semi-interpenetrating polymer networks (SIPNs) based on polyurethane (PU) and epoxy maleate of bisphenol A (EMBA) was studied using thermogravimetry technique. The PU-EMBA SIPNs were prepared after a sequential procedure using mixtures of PU and EMBA solutions in dimethylformamide (DMF). The mixture was thermally cured at 120℃. when EMBA crosslinked and included in its networks structure the PU linear polymer. The thermal decomposition of the studied SIPNs was examined in the range of temperatures between 40 and 600℃. in dynamic conditions and in presence of oxygene. The tested SIPNs decompose in three stages, the main decomposition is between 290 and 480℃. The experimental kinetic parameters estimated using Coats-Redfern, Ozawa and Levi-Reich methods showed that the synthesized SIPNs degrade by a complex mechanism, with statistical rupture of the main polymeric chain.