【作者】 邓胜吉；

【导师】 王香梅；

【作者基本信息】 中北大学 ， 生物化工， 2010， 硕士

【摘要】 水性聚氨酯具有良好的耐低温性、柔韧性和耐磨性,且具有无毒等优点,将丙烯酸酯改性水性聚氨酯,不仅可以保留聚氨酯原有的优异性能,还可以增加涂膜的耐水性、耐化学性和耐候性,使乳液及胶膜的性能得到明显的改善。但丙烯酸酯改性水性聚氨酯也存在一些问题,如：丙烯酸酯改性水性聚氨酯乳液稳定性差,同时PUA复合乳液作高档涂料时仍存在涂膜耐水性不足等缺陷。本研究针对丙烯酸酯改性水性聚氨酯所存在的缺点,采用种子乳液聚合方法,制备了聚氨酯-聚丙烯酸酯共聚物复合乳液。通过控制聚合工艺条件,在一定条件范围内制备了随着固含量提高,表观粘度逐渐降低的复合乳液。从而能解决乳液流动性差、膏化现象使复合乳液稳定性下降问题,也可提高作高档涂料时涂膜耐水性问题。在实验过程中,以二羟甲基丙酸(DMPA)为亲水扩链剂、羟甲基丙烯酰胺(N-MAM)为封端剂,自乳化法制备了端乙烯基水性聚氨酯乳液。研究了温度、-NCO/-OH摩尔比、聚合物多元醇种类及相对分子质量、DMPA用量、中和剂种类及中和度等合成工艺条件对乳液及涂膜性能的影响。通过对乳液粒径测定表明：随着DMPA用量的增加,乳液的粒径减小、稳定性增加。在水性聚氨酯最佳合成工艺的基础上,以端乙烯基水性聚氨酯为种子乳液,采用半连续法向种子乳液中滴加丙烯酸酯单体,制备了聚氨酯-聚丙烯酸酯复合乳液。利用FTIR、13C-NMR谱图、DSC谱图等分析仪器,对制备的聚氨酯-聚丙烯酸酯进行了结构分析；同时研究了反应温度、引发剂种类及用量、复合乳化剂SDS-OP10配比及用量、丙烯酸单体与乙烯基水性聚氨酯的质量比等改性工艺条件对复合乳液及涂膜性能的影响。FTIR、13C-NMR谱图、DSC谱图等表明：所制备的复合乳液形成了聚氨酯-聚丙烯酸酯共聚物；通过对复合乳液粒径、表观粘度和涂膜水接触角测定表明：随着甲基丙烯酸甲酯(MMA)用量的增加,复合乳液乳胶粒径增加,复合乳液表观粘度降低,涂膜水接触角增大,涂膜耐水性提高。在最佳条件下,制备了固含量为48.3%,而表观粘度为91.2mPa.s的复合乳液。鉴于负离子对人体有保健作用。本研究将负离子添加剂添加到丙烯酸酯改性的水性聚氨酯复合乳液中制备成涂层剂。通过正交实验设计方案,确定了可释放负离子丙烯酸酯改性的水性聚氨酯涂层剂的最佳工艺条件,并用于纯棉布和涤棉布的处理。通过实验表明：所制备的涂层剂处理纯棉布和涤棉布可释放负离子数分别达1390个/cm3和1200个/cm3。更多还原

【Abstract】 Water-based polyurethane owns many excellent properties such as dramatic low temperature resistance, terrific flexibility, perfect abrasion resistance, non-toxic, and so on. water-based polyurethane was modified by acrylate, not only to retain the outstanding properties of polyurethane, but also to improve water-resistance, chemical resistance, weather resistance of the film, which improves the properties of the emulsion and the film significantly. Unfortunately, water-based polyurethane modified acrylate still has some problems, such as poor stability of emulsion and deficient water-resistance for advanced paint.In this thesis, polyurethane-polyacrylate copolymer composite emulsion was prepared by means of seed emulsion polymerization to improve the drawbacks of the acrylate modified water-based polyurethane. By controlling the process of polymerization, the composite emulsion was prepared, and its apparent viscosity decreased gradually along with the increase of its solid content. The problems of the composite emulsion such as poor mobility and paste phenomenon can be solved successfully, and the emulsion can be applied as advanced paint.During the experiment, water-based polyurethane which was dimethylol propionic acid (DMPA) as the hydrophilic chain extender and hydroxymethyl acrylamide (N-MAM) as capping agent. The influences of the reaction temperature,-NCO/-OH molar ratio, the types polymer of polyols and relative molecular mass, and the amount of DMPA, different types of neutralizer, and the ratio of neutralization on coating properties were investigated thoroughly. Determination by latex particle size showed that:with the increased use of DMPA, emulsion particle size decreases and stability increases.Polyurethane polyacrylate composite emulsion was synthesized while vinyl termi-nated polyurethane was used as seed emulsion, acrylate monomer was added to it using semi-continuous. During the copolymerization process, the influences of polymerization parameters, including reaction temperature, different initiators,ratio of emulsifier SDS-OP10 and the amount of them, acrylic monomers and vinyl weight ratio of polyurethane were investigated thoroughly. Polyurethane-polyacrylate’s structure was analyzed by using FTIR, 13C-NMR spectra, DSC spectra and other analytical instruments, the results show that Polyurethane-polyacrylate copolymer were synthesized, and with the amount of methyl methacrylate (MMA) increased, composite latex particle size water contact angle of the coating increased, and its water-resistant improved. Under optimal conditions, the composite emulsion was prepared with solid content of 48.3% and the apparent viscosity 91.2 mPa.s. In view of the role of negative ions on the human body health, the coating agent was synthesized by adding anion additives to water-based polyurethane composite latex which was obtained in this study. In this thesis,the best optimum condition under this negative ions were released from the emulsion was determined, which was also used in the cotton cloth and polyester-cotton fabric processing.the results show that those kind of cotton cloth and polyester-cotton fabric can release negative ions, up to 1390/cm3 and 1200/cm3 respectively.更多还原