【摘要】 以4,4′-二苯基甲烷二异氰酸酯(MD I)和聚四氢呋喃均聚醚(PTMG)为原料合成聚氨酯(PU)预聚体,再分别与BDO、MOCA、HQEE扩链剂及混合扩链剂制备PU弹性体。讨论了预聚体NCO基含量、聚醚软段相对分子质量、三羟甲基丙烷(TMP)小分子醇含量及扩链剂类型对PU弹性体力学性能的影响。结果表明,提高预聚体NCO基含量可使PU弹性体的硬度、撕裂强度和300%模量明显提高;当预聚体NCO基含量基本相同时,软段Mn=2000比Mn=1000的PU冲击弹性高;混合扩链剂中的TMP质量分数超过30%时,弹性体的力学性能明显下降;BDO-PU的拉伸强度比HQEE-PU的强度高出70%以上,撕裂强度比HQEE-PU低了40%以上,硬度比MOCA-PU小。更多还原

【Abstract】 The PU prepolymer was synthesized from PTMG and MDI.The polyurethane elastomer made from the prepolymer,BDO,MOCA,HQEE or mixed chain extender respectively was studied.The effects of percent NCO in prepolymer,polyether soft segment molecular weight,content of triol and types of chain extender on the mechanical properties of polyurethane elastomer were investigated.The results showed that the hardness,tear strength and 300% modulus was enhanced rapidly when percent NCO in prepolymer was increased.The resilience and elongation at break of PU made from Mn=2000 soft segment were more than that of Mn=1000 soft segment when the amount of prepolymer NCO was almost same.The mechanical properties of elastomer was decreased significantly when the TMP exceeded 30% in chain extender.Meanwhile,the tension strength of BDO-PU was 70% more than that of HQEE-PU.The tear strength of BDO-PU was 40% less than that of HQEE-PU.The hardness of BDO-PU was less than that of MOCA-PU.更多还原