聚氨酯树脂对单组分湿气固化密封胶耐热粘接性能的影响

Effect of polyurethane resin on the heat resistance bonding properties of one-component moisture curing sealant

合成了不同种类的端—NCO的聚氨酯树脂,讨论了聚氨酯树脂含量、R值、异氰酸酯种类、不同分子量聚醚多元醇对聚氨酯密封胶耐热粘接性的影响。研究结果表明:(1)不同聚氨酯树脂含量的聚氨酯密封胶常温养护7 d粘接面均为100%CF,而高温120℃后,底涂与部分聚氨酯密封胶出现脱落。(2)密封胶耐热粘接性受—NCO%含量影响较大,当密封胶—NCO%含量>1.10%,保持90%CF时间可达18 h。(3)添加单体可提升耐热粘接性,反应活性适中、结构适合的HDI三聚体效果最好。(4)MDI制备的密封胶耐热粘接效果最好,HDI、TDI次之,IPDI最差。(5)改变聚醚三元醇的相对分子量,对密封胶的耐热粘接性略有差异,但影响不大。

Different types of end—NCO polyurethane resins were synthesized,and the effects of polyurethane resin content,R value,isocyanate type,and polyether polyols with different molecular weights on the heat resistance bonding of polyurethane sealant were discussed.The research results showed that,(1)Polyurethane sealants with different polyurethane resin contents had a bonding surface of 100%CF after curing at room temperature for 7 d,but after high temperature treatment at 120℃,some polyurethane sealants and primers exhibited detachment.(2)The heat resistance bonding of sealant was greatly affected by the—NCO%content.When the—NCO%content of sealant was greater than 1.10%,the holding time of 90%CF could reach 18 hours.(3)The addition of monomers could enhance the heat resistance bonding,and the HDI trimer with moderate reactivity and suitable structure had the best effect(.4)The sealant prepared with MDI had the best heat resistance bonding effect,followed by HDI and TDI,and IPDI was the worst(.5)Changing the relative molecular weight of polyether polyols had a slight difference in the heat resistance bonding of the sealant,but the impact was not significant.