HTBN/PTMG双软段聚氨酯弹性体的制备及力学性能研究

以甲苯二异氰酸酯(TDI)、端羟基聚丁二烯-丙烯腈共聚物(HTBN)、聚四氢呋喃醚二醇(PTMG)为主要原料,3,5-二甲硫基甲苯二胺(DMTDA)为扩连剂,采用浇铸法制备了聚氨酯弹性体。研究了聚氨酯预聚体中NCO含量、HTBN/PTMG质量比、PTMG相对分子质量和改变扩链剂用量以及热处理时间对聚氨酯弹性体力学性能的影响。结果表明,低相对分子质量PTMG和高热处理温度有利于提高聚氨酯弹性体的力学性能,当聚氨酯预聚体中HTBN/PTMG的质量比为50∶50、NCO质量分数为5.98%、NCO/NH2摩尔比为1.20、115℃下热处理2 h时,聚氨酯弹性体的力学性能最佳。

Preparation and Mechanical Properties of Polyurethane Elastomers with Two Soft Segments of HTPB/PTMG

A series of polyurethane elastomers were prepared by casting method using toluene diisocyanate（TDI）,hydroxy-terminated butadiene-acrylonitrile copolymer（HTBN） and polytetrahydrofuran glycol（PTMG） as the main raw materials,and using 3,5-dimetylthio-2,4-diaminotoluene or 3,5-dimetylthio-2,6-diaminotoluene（DMTDA） as chain extender.The influences on the mechanical properties of polyurethane elastomers were studied,including the content of NCO in polyurethane prepolymer,the mass ratio of HTBN/PTMG,the molecular weight of PTMG,the dosage of chain extender and heat treatment time.The results showed that the lower molecular weight of PTMG and the higher temperature of heat treatment were both favorable for increasing the mechanical properties of polyurethane elastomers.When the mass ratio of HTBN/PTMG was 50∶50,the content of NCO was 5.98%,the molar ratio of NCO/NH2 was 1.20 and the heat treatment time was 2 h at 115℃,the mechanical properties of polyurethane elastomers were the best.