硅改性疏水型水性聚氨酯的制备及性能研究

Preparation and properties of silicon modified hydrophobic waterborne polyurethane

采用原位聚合的方法将γ-氨丙基三乙氧基硅烷(KH550)引入到含有硅氧烷(PDMS)的聚氨酯预聚体中,得到一系列KH550封端的硅改性水性聚氨酯(KH550-SiWPU).结合FT-IR、XPS、热重分析仪、接触角测角仪等表征手段研究KH550封端、PDMS改性对系列水性聚氨酯性能的影响.结果表明:当PDMS含量为8%,KH550封端含量为40%时,所得水性聚氨酯的疏水性能最佳,水滴角可达105°,吸水率为24.6%,表面能为25.06 mN/m,相比未改性水性聚氨酯(水滴角为81°,吸水率为88.4%,表面能为44.03 mN/m)水滴角提升30%,吸水率下降72%,表面能下降43%.同时,热稳定性和力学性能等其他性能也得到一定程度的提升,进一步表明KH550封端,PDMS改性对于提升水性聚氨酯的综合性能尤其是疏水性能具有重要作用.

In-situ polymerization was used to introduce γ-aminopropyltriethoxysilane(KH550) into the polyurethane prepolymer containing siloxane(PDMS) to obtain a series of KH550-terminated silicon-modified waterborne polyurethane(KH550-SiWPU).The effects of KH550 capped end and PDMS modification on the properties of series waterborne polyurethanes were studied by FT-IR, XPS, TG analyzer, contact angle goniometer and other characterization methods.The results show that when the PDMS content is 8% and the KH550 end-capping content is 40%, the hydrophobic property of the obtained waterborne polyurethane is the best.The water droplet angle could reach 105°, the water absorption rate is 24.6%, and the surface energy is 25.06 mN/m.Compared with unmodified waterborne polyurethane(the water droplet angle is 81°, the water absorption rate is 88.4%, and the surface energy is 44.03 mN/m), the water droplet angle is increased by 30%, the water absorption rate is decreased by 72%, and the surface energy is decreased by 43%.Meanwhile, other properties such as thermal stability and mechanical properties have also been improved to some extent.Furthermore, the modification of KH550 end-capping and PDMS play an important role in improving the comprehensive properties of waterborne polyurethane, especially the hydrophobic properties.