Thermal Pyrolysis Characteristics Of Ethyleneoxid/Tetrahydrofuran (EO/THF) Copolyether Urethane

The thermal decomposition characteristics of PET, PET copolyether urethane, PET glue copolyether urethane were investigated with differential scanning calorimetry and thermogravimetry analysis (DSC-TG) under general nitrogen atmosphere and high pure nitrogen atmosphere. The activation energy was calculated by Freeman-Carroll equation. The relationship between pyrolysis production and temperature of PET, PET copolyether urethane, PET glue copolyether urethane were investigated by Pyrolysis Gas-Chromatography-Mass Spectrometry (Py-GC-MS) . The pyrolysis mechanism of PET, PET copolyether urethane, PET glue copolyether urethane were studied by analysing pyrolysis production.The results show that the TG curves of PET and PET copolyether urethane have only one stage. The thermal decomposition of PET copolyether urethane is exothermic reaction under general nitrogen atmosphere while endothermic reaction under high pure nitrogen atmosphere. The TG curve of PET glue copolyether urethane has two stages. One is the decomposition of BG and the other is the decomposition of PET copolyether urethane.The pyrolysis products of PET, PET copolyether urethane, PET glue copolyether urethane are mainly the multimer of ethylene oxide tetrahydrofuran and a small quantity of monomer under low temperature. Along with the increase of temperature, pyrolysis production has great change. The content of multimer is decreased in evidence. The monomer and small molecule compounds in the product such as CO , ethene, ethane, propylene, propane, butylene, methyethy aether ,furan, ethylene ether, acrolein, butanal, butenoic aldehyde etc. are increased with heating temperature. CO , ethene, ethane come from the rupture of carbon-carbon bond and carbon-oxygen bond of PET and PET copolyether urethane. The small molecules such as ethene, ethane, propylene, propane, butylene, methyethy aether ,furan, ethylene ether, acrolein, butanal, butenoic aldehyde are formed because of the differences of rupture location and residual group.The pyrolysis mechanism of PET copolyether urethane is depolymerization cooperating with function group rupture.