高固含量氟硅改性水性聚氨酯的制备与性能

Preparation and Properties of High Solid Contents Fluoro-silicone Polyurethane

如何减少分散介质水的添加量,提高水性聚氨酯(WPU)乳液的固含量以及WPU胶膜表面的疏水性是WPU推广应用的关键。通过预聚-丙酮法进行合成,采取分步乳化的方法制备水性聚氨酯,首先以聚己二酸-1,4-丁二醇酯(PBA)为软段,异佛尔酮二异氰酸酯(IPDI)、氟二醇(FDO)和乙二氨基乙磺酸钠(AAS)为硬段,将合成的聚氨酯预聚体乳化得到小粒径含氟聚氨酯乳液F-WPU1;同时以PBA与聚二甲基硅氧烷(PDMS)为软段,六亚甲基二异氰酸酯(HDI)、IPDI、1,4-丁二醇(BDO)和AAS为硬段,合成高固含量的含硅聚氨酯预聚体Si-WPU2,再用F-WPU1乳液去乳化该预聚体,制备了高固含量的水性聚氨酯乳液Si-F-WPU3c,其固含量可达60%,乳液性能稳定。与未改性前相比,胶膜的表面疏水性提高,在去离子水中浸泡24 h后力学性能也无明显改变,在5%硫酸溶液和99%乙醇中浸泡24 h后,溶胀性也有明显改善。

How to reduce the amount of water in the dispersion medium, increasing the solid contents of the emulsion and the hydrophobicity of waterborne polyurethane(WPU)film surface was the key to promote the application of waterborne polyurethane.The waterborne polyurethane was prepared by the prepolymer-acetone method and stepwise emulsification.Taking poly-1,4-butanediol adipate(PBA)as the soft segment, isophoronediisocyanate(IPDI),fluorodiol(FDO)and N-(2-aminoethyl)-2-aminoethane sulphonic sodium(AAS)as the hard segment, the small particle size emulsion F-WPU1 were obtained by emulsified.Meanwhile, taking PBA and polydimethylsiloxane(PDMS)as the soft segment, hexamethylenediisocyanate(HDI),IPDI,1,4-butanediol(BDO)and AAS as the hard segments, silicon-containing prepolymer(Si-WPU2)was synthesized.Finally, F-WPU1 emulsion was used to emulsify Si-WPU2 polyurethane solution, and the high solid content waterborne polyurethane emulsion Si-F-WPU3 c was prepared.Its solid content was up to 60%,and the emulsion performance was stable.Comparing with the unmodified one, the surface hydrophobicity of the film was improved, and the mechanical properties of the film was not significantly changed after immersing in deionized water for 24 hours.And the swelling property was also significantly improved after immersing in 5%sulfuric acid solution and 99%ethanol for 24 hours.