摘要
以聚四氢呋喃均聚醚(PTMG)和甲苯二异氰酸酯(TDI-100)为原料合成聚氨酯预聚体,再分别与扩链剂TX-2、E300和二者混合物反应制备聚氨酯(PU)弹性体。研究了TX-2含量、预聚体NCO基含量、扩链系数、聚醚软段相对分子质量对弹性体力学性能的影响。结果表明,提高扩链剂中TX-2含量,胶液流动时间延长,PU弹性体的力学性能变化不大;预聚体NCO基质量分数增加,弹性体的硬度、300%定伸应力、拉伸强度和撕裂强度明显提高,拉断伸长率下降;当扩链系数增加时,弹性体的拉伸强度、300%定伸应力和拉断伸长率均明显提高,但当扩链系数>1时,上述各项性能指标迅速降低;随着软段相对分子质量的增加,弹性体的硬度、300%定伸应力、拉伸强度和撕裂强度均下降,拉断伸长率和冲击弹性增加。
Polyurethane prepolymer was synthesized by using polytetramethylene glycol（PTMG）and 2,4-tolylene diisocyanate（TDI-100）as raw materials.Polyurethane elastomers were prepared by using 2,4-diamino-3,5-dimethylthio chlorobenzene（TX-2）,3,5-dimetylthio toluene dianiline（E300）and their mixture as chain extenders.The influence of the mass fraction of TX-2,mass fraction ofNCO in prepolymer,chain extension coefficient and molecular weight of soft segment on the mechanical properties of polyurethane elastomer were investigated.The results showed that the flow time increased when the mass fraction of TX-2was increased,while the mechanical properties of the elastomer changed little.The hardness,modulus at 300%elongation,tensile strength and tear strength was enhanced rapidly when percentage of NCO in prepolymer was increased,but elongation at break and impact elasticity decreased.When chain extension coefficient increased,the tensile strength,modulus at 300% elongation and elongation at break of PU significantly improved.But when the chain expansion coefficient exceed 1,properties mentioned above was rapidly decreased.The hardness,modulus at 300% elongation,tensile strength and tear strength was decreased when molecular weight of soft segment was increased,but the elongation at break and impact elasticity performance improved.
作者
郝亚暾
HAO Ya-tun(Shanxi Provincial Institute of Chemical Industry, Taiyuan 030021,China)
出处
《特种橡胶制品》
2016年第6期28-31,共4页
Special Purpose Rubber Products
