聚氨酯-聚丙烯酸酯复合胶乳的制备及其性能研究

通过丙酮工艺法,分别制备了含有羧基作为内乳化剂的乙二胺扩链型水性聚氨酯(EDAWPU)和甲基丙烯酸β羟乙酯(HEMA)封端的水性聚氨酯(VLWPU)。为了改善水性聚氨酯(WPU)膜的性能,采用无皂乳液法制备了未交联型和交联型水性聚氨酯/聚丙烯酸酯复合乳液(UCPUA和CPUA)。通过红外对EDAWPU和VLWPU的化学结构进行了确认。使用TEM发现CPUA复合乳胶的形貌是以聚丙烯酸酯为核,聚氨酯为壳的核/壳结构。CPUA和UCPUA的分子量分别为310934和86522。从DSC曲线中能观察到CPUA膜的玻璃化转变温度相对较高。在CPUA膜中,通过交联CPUA的拉伸强度也得到增加。所以结果显示CPUA复合乳胶在硬度,附着力,柔韧性,光泽度和耐水性等方面均显示出了优异的性能。

Synthesis and Properties of Polyurethane/Polyacrylate Composite Emulsion with Core-Shell Structure

Ethylenediamine extended and ethylene glycol methacrylate capped anionic waterborn polyurethanes(EDAWPU and VLWPU) containing the carboxyl groups which serve as internal emulsifier were prepared by acetone process,respectively.In order to improve the performances of waterborne polyurethane(WPU) films,the uncrosslinked and crosslinked polyurethane / polyacrylate(UCPUA and CPUA) composite emulsions with core and shell structure were prepared via soap-free emulsion polymerization techniques.The chemical structures of the EDAWPU and VLWPU were confirmed by FT-IR.The core-shell structure of CPUA was exposed by the TEM images which show that the core and shell consist of acrylic polymer and polyurethane,respectively.The average molecular weights of CPUA and UCPUA are 310934 and 86522,respectively.The TGA show that the CPUA with thermal decomposition temperature Td = 276.12℃ presents better thermal stability than that of UCPUA(Td = 269.3℃).The relatively higher glass transition temperatures Tg were observed for CPUA films from DSC curves.The tensile strength of CPUA films is also improved by the cross-linking between the polyurethane and polyacrylate in the films.All the results show that the CPUA exhibits superior performance properties in terms of hardness,adhesion,flexibility,glossiness and water resistance.