聚碳酸亚丙酯聚氨酯弹性体的合成与性能

Synthesis and Properties of Poly(Propylene Carbonate)Polyurethane Elastomer

以聚碳酸亚丙酯二醇、二苯基甲烷二异氰酸酯(MDI)和1,4-丁二醇(BDO)等为原料,采用预聚体法合成了聚碳酸亚丙酯聚氨酯弹性体(PUE-PPC)。研究表明,PUE-PPC拉伸强度和撕裂强度优于聚醚型弹性体;与聚酯型弹性体相比,具有较好的水解稳定性,经35d浸泡后,其拉伸强度保持率高出33%。研究了异氰酸酯指数(R)、预聚体-NCO基含量、扩链剂种类等对PUE-PPC力学性能的影响。结果表明,随着R值减小,弹性体的拉伸强度和撕裂强度先增大后减小,并在R=1.05时达到最大值,断裂伸长率则一直增大;随着-NCO基含量的增加,弹性体的拉伸强度和撕裂强度提高,而断裂伸长率减小;扩链剂链长越短,弹性体力学性能越好。

Poly(propylene carbonate)-based polyurethane elastomers(PUE-PPC)were prepared by prepolymer process with 4,4'-diphenylmethane diisocyanate(MDI)and 1,4-BDO as raw materials and the properties of elastomers were studied.The results show that,PUE-PPC exhibits better mechanical properties compared with polyether type elastomer.Meanwhile,it is more resistant to hydrolysis than polyester type elastomer,after 35 dsoaking in water,the retention of tensile strength is 33% higher than that of polyester elastomer.The effects of isocyanate index(R),-NCO content in prepolymer,different chain extenders were also discussed.With decreasing R,the elongation at break increases,while tensile strength and tearing strength first increase and then decrease,and reach the maximum at R=1.05;when the NCO content increases,tensile strength and tearing strength increase,but the elongation at break reduces;the elastomer containing the shorter chain extender has excellent mechanical properties.