端羟基聚丁二烯型水性聚氨酯的制备、性能及交联改性

Preparation and Properties of HTPB Waterborne Polyurethane and Cross-Linking Modification

以3,6-二氧杂-1,8-辛烷二硫醇(BOODT)与异氰酸酯后扩链制备端羟基聚丁二烯(HTPB)型水性聚氨酯(WPUHS)分散液,再在紫外光照射下通过硫醇与双键的反应对水性聚氨酯分散液进行交联改性。研究了HTPB含量对分散液的稳定性、WPUHS的耐水性及力学性能的影响。结果表明:当HTPB含量约为4%时,分散液的粒径、WPUHS的耐水性及力学性能相对较好。同时探讨了交联改性中光引发剂种类及光照时间对胶膜交联密度及力学性能的影响,结果表明:安息香二甲醚为引发剂时,交联后胶膜的交联密度及力学性能较优;且光照时间为1 h时胶膜力学性能最优。

The hydroxyl-terminated polybutadiene （ HTPB ） waterborne polyurethane dis- persions （WPUHS） were successfully synthesied by the post-chainextension of 3,6-dioxa- 1, 8-octanedithiol （BOODT） and isocyanate click chemistry, then modified with cross-linking of thiol-ene under UV irradiation condition. The effects of HTPB content on the stability of dispersions, water resistance and mechanical properties of polyurethane films were studied. The results showed that WPUHS dispersions with HTPB content of 2. 1% presented smaller particle size and its films had better water repellence and mechanical properties. Meanwhile, the effect of photoinitiator-types and exposure time on the mechanical properties of polyure- thane films were investigated. The results demonstrated that the crosslinking density and me- chanical properties of WPUHS films with benzoin dimethyl ether as photoinitiator were better than those with benzophenone as photoinitiator. The mechanical properties of WPUHS films were optimal when the exposure time was 1 h.