一种硅烷封端聚氨酯的合成及其在密封胶制备中的应用

Synthesis of a silane-terminated polyurethane and its application in sealant preparation

设计了一种不同于以往同类型硅烷封端聚氨酯(SPU)预聚体的合成方案。以一种端—NCO硅烷和端—OH聚氨酯预聚体封端反应,得到硅烷封端聚氨酯预聚体。然后以此为基料,并添加催化剂和补强填料,通过配方筛选,制备了一种弹性密封胶产品。研究结果表明:当以MDI-100制备的产品作为调胶基料,以KH-540作为偶联剂,选择使用改性有机锡催化剂,w(纳米碳酸钙)=25%,w(疏水性白炭黑)=2%(相对于总质量而言)时,制备的密封胶综合性能较优。该密封胶克服了聚氨酯和硅酮密封胶的缺点,具有湿气固化特性,胶层不起泡、弹性好、可涂饰,综合性能优异,并且合成过程简单易控,产物稳定,目前已在工程密封领域得到了应用。

A synthesis scheme different from previous silane-terminated polyurethane(SPU)prepolymer was designed.A silane-terminated polyurethane prepolymer was obtained by the capping reaction of—NCO silane and—OH terminated polyurethane prepolymer.Then,using it as the base material,adding catalyst and reinforcing filler,an elastic sealant product was prepared through formula selection.The research results showed that when the product prepared by MDI-100 was used as the base material for adhesive conditioning,KH-540 was used as the coupling agent,modified organotin catalyst was selected,w(nano calcium carbonate)=25%,w(hydrophobic silica)=2%(relative to the total mass),the comprehensive performance of the sealant prepared was relatively excellent.The sealant overcame the shortcomings of polyurethane and silicone sealant,had moisture-curing properties,the adhesive layer was non-foaming,elastic and paintable,and had excellent overall performance.Moreover,the synthesis process was simple and easy to control,the product was stable,and had been applied in the field of engineering sealing.