纤维素纳米晶体/石墨烯复合溶液对双组份水性聚氨酯涂料性能的影响

随着大众生活品质的提升,对于水性木器涂料的性能要求也不断提高,无毒环保、力学性能优良的水性涂料在家居木制品行业的应用需求不断增多。本研究围绕水性木器涂料,以纤维素纳米晶体溶液(CNC)为分散液,以生物质源石墨烯(Gr)为涂料改性剂,开发出高硬度、高附着力、高耐磨特性的双组份水性聚氨酯涂料(2K-WPU),改善水性涂料力学性能不理想的现状,以扩大其在家居木制品行业的应用范围。研究结果表明:CNC/Gr复合溶液的添加,使2K-WPU固化后涂层的硬度、耐磨性有不同程度的提高,而光泽度有所下降。其中,涂层附着力在CNC/Gr不同添加量条件下保持1级不变;铅笔硬度由5H提高至6H;CNC质量浓度为4%,Gr添加量占比为3%时,涂层的耐磨性最好,磨耗量为0.0 453 g;涂层光泽度随CNC/Gr添加量增加,由21.8%降低至6.1%。CNC/Gr改性水性涂料的方法,绿色环保且实验步骤简单易操作,为开发性能优良的功能型水性木器涂料提供有效途径。

双组份水性涂料适用期判定方法的研究

针对配方研发的热点问题——涂料适用期,对与之相关的漆膜硬度、光泽、雾影等方面展开了研究。结果发现,针对不同的树脂体系,判断适用期的方法不同,即使对同一个树脂体系来说,不同方法测试得出的适用期的长短也不同,因此要综合不同测试方法来判断适用期的长短。研究还发现,从微观角度来看,双组分水性聚氨酯涂料中NCO含量的变化及其形成涂膜的表面微观形貌的变化对双组分水性聚氨酯涂料的适用期有重要影响。本文还对欧洲家装木器市场中双组分水性聚氨酯涂料的应用做了基本总结。

Preparation and Characterization of Two-component Waterborne Polyurethane Comprised of Water-soluble Acrylic Resin and HDI Biuret

A two-component waterborne polyurethane(2K-WPU) was prepared by mixing water-soluble acrylic resin and hexamethylene diisocyanate biuret, and then diluted for phase inversion with water. Compared with water-soluble acrylic resin, the phase inversion of 2K-WPU occurs at lower water content. It is indicated by TEM that 2K-WPU parti-cles show a core-shell structure, in which HDI biuret is encapsulated by hydrophilic acrylic resin. 2K-WPU emulsion with HDI biuret has larger particle size and narrower distribution index, while for 2K-WPU emulsion with HDI iso-cyanurate, the latex not only has large particle size, but also has two-peak distribution. FTIR shows that the reaction be-tween HDI biuret and acrylic resin can complete in 12h. In addition, studies on effect of composition of acrylic resin on performance of 2K-WPU show that narrowing the polar difference between water-soluble acrylic resin and HDI biuret and improving the miscibility of two components are the key to prepare the transparent and high gloss films with high crosslinking density.