新型有机硅改性聚氨酯填缝胶的合成及应用

Synthesis and application of new polyurethane sealant modified by silicone

以n(—NCO)∶n(—OH)=2.0制备出—NCO封端的聚氨酯预聚体,再以n(Si—OH)∶n(—NCO)=1.8加入端羟基聚二甲基硅氧烷,得到硅羟基封端的聚氨酯预聚体。然后加入填料、增塑剂、交联剂和催化剂等助剂混合搅拌均匀,制得新型有机硅改性聚氨酯填缝胶。探讨了各因素对聚氨酯填缝胶性能的影响,经测试,其拉伸强度为0.66 MPa,断裂伸长率为433%,粘结强度为0.48 MPa。

The polyurethane prepolymers of--NCO terminated was prepared by the ratio of--NCO/-OH 2.0,atterwards,the polyurethane prepolymers of silicon hydroxyl-terminated was prepared by polysiloxane of hydroxyl-terminated by the ratio of Si--OH/-NCO=1.8. The filler,plasticizer, cross-linking agent and catalyst were mixed to prepare the new polyurethane sealant modified with silicone. The influences of different elements on properties of modified polyurethane sealant were discussed. And their relevant properties were tested,the test result of tensile strength is 0.66 MPa,the percentage of breaking-elongation is 433%, the bonding strength is 0.48 MPa .