添加剂对EO/THF共聚醚聚氨酯热氧降解的影响

Effects of Additives on the Thermooxidation of Ethylene Oxide/Tetrahydrofuran(EO/THF) Copolyether urethane

采用ＦＴＩＲ及ＮＭＲ技术研究固化催化剂、增塑剂、抗氧剂及聚醚二元醇结构对聚醚聚氨酯热氧降解过程的影响． 增塑剂邻苯二甲酸二丁酯（ＤＢＰ） 在聚醚聚氨酯热氧降解过程中起阻降作用． 而固化催化剂二月桂酸二丁基锡（ＤＢＴＤＬ） 和三苯基铋（ＴＰＢ） 对聚醚聚氨酯的热氧降解有着截然不同的影响． 以聚乙二醇（ＰＥＧ） 为聚醚二元醇的聚醚聚氨酯与环氧乙烷／ 四氢呋喃（ＥＯ／ＴＨＦ） 共聚醚聚氨酯具有相似的降解机理；ＤＢＰ增塑时ＰＥＧ 聚醚聚氨酯比共聚醚聚氨酯具有较低的热氧稳定性，而硝酸酯增塑时ＰＥＧ体系比共聚醚体系表现出较高的热氧稳定性．

The effects of plasticizer, curing agent, antioxidant as well as glycol structure on the thermooxidation of EO/THF copolyether urethane have been investigated by FT IR and NMR techniques. It is found that plasticizer dibutyl phthalate(DBP) has some stabilizing effect on the polyether urethane, but not on the degradation mechanism. Dibutyltin dilaurate(DBTDL) and triphenyl bismuth(TPB) show striking different behavior towords the thermooxidatin of polyurethane. Being plasticized with DBP, polyurethane with PEG as soft segments is more susceptible to thermooxidation than that with EO/THF copolymer, whereas the polyurethane plasticized with nitrate esters is less sensitive to thermooxidation.