PTMG/TDI型聚氨酯弹性体的制备及力学性能研究

摘要

The cast polyurethane elastomers ( PUE) was prepared using PTMG and TDI as materials, MOCA and E-300 as chain extender by prepolymer method. The effect of the NCO content of prepolymer, the molecular weight of polyether soft segment, the type of chain extender and the coefficient on mechanical properties of polyurethane elastomer were respectively discussed. The results showed that the PUE hardness, tensile strength, tear strength and tensile modulus at 300%became better when the NCO content was increased, the elongation at break was decreased and the permanent distortion was hardly changed. With increasing the molecular weight of soft segment heightened, the PUE hardness, tensile strength, tear strength and 300% modulus decreased gradually, while the elongation at break and the permanent distortion increased. When other conditions were the same, E-300 was better than MOCA to the mechanical properties of polyurethane elastomer.%以聚四氢呋喃醚二醇(PTMG)、2,4-甲苯二异氰酸酯(TDI)、3,3′-二氯-4,4′-二胺基二苯甲烷(MOCA)或3,5-二甲硫基甲苯二胺(E-300)为主要原料,采用预聚体法合成浇注型聚氨酯弹性体(PUE).分析了预聚体NCO基含量、PTMG软段相对分子质量、两种扩链剂以及扩链系数对PUE力学性能的影响.结果表明,随着预聚体NCO基含量增加,PUE的硬度、拉伸强度、300％定伸应力和撕裂强度提高,扯断伸长率下降,扯断永久形变发生微小变化；随着软段相对分子质量的不断提高,PUE的硬度、拉伸强度、300％定伸应力和撕裂强度缓慢下降,而扯断伸长率和扯断永久形变升高；在其它条件相同时,扩链剂E-300与MOCA相比,综合力学性能较好.