Thermal decomposition of bisphenol A-based polyetherurethanes blown with pentane Part Ⅰ—Thermal and pyrolytical studies

摘要

In this work thermal decomposition of ethoxylated 2,2-bis-(4-hydroxyphenyl)propane (BPA) and oxyalkylenated 2,6-toluyldiamine (TDA)-based rigid polyurethane (PU) foam, blown with pentane, is described. Thermogravimetry coupled with mass spectrometry (TG-MS) and thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR) results of the evolution of volatile products during the degradation and gas chromatography coupled with mass spectrometry analysis of condensed products of PU foam pyrolysis (Py/GC-MS) are presented. Four temperature ranges of volatile products emission were detected under inert atmosphere—pentane used as blowing agent volatilizes in first range, the second one is dominated by dissociation reaction of urethane bonds by which first order amines, CO_2 and vinyl bonds, are formed, while complex reactions with formation of secondary amine and CO_2 occur in the third stage. Fourth stage is visible by further CO_2 evolution. Ethylene oxide and derivatives of dioxane, formed due to the presence of oxyalkylene chains, act as fuel during the burning of PU foam.