水性聚氨酯丙烯酸酯复合乳液的合成、表征与性能研究

发布时间：2018-05-25 13:29

本文选题：水性聚氨酯 + 聚丙烯酸酯　；参考：《太原理工大学》2017年硕士论文

【摘要】：水性聚氨酯丙烯酸酯(WPUA)兼具聚氨酯(PU)与聚丙烯酸酯(PA)的优点,安全环保,价格低廉,成膜性能好,物理机械性能优异,被广泛地应用于涂料、胶黏剂、纺织印染等领域。然而,合成WPUA时,常以含羧基的WPU为自乳化剂,PA的含量很难超过40%,制备成本较高;分子链上含亲水的羧基,其膜的耐水性能较差。为解决这些问题,本文采用异佛尔酮二异氰酸酯(IPDI)、聚氧化丙烯二醇(PPG)、2,2-二羟甲基丙酸(DMPA)、1,4丁二醇(BDO)合成异氰酸基封端的聚氨酯预聚物,进一步用含羟基的乙烯基化合物封端,经中和、乳化,合成可聚合的WPU预聚体乳液。将其和丙烯酸酯聚合,分别合成化学键连接的高PA/PU比例、有机硅改性、有机硅氟共改性的WPUA复合乳液,并研究了其物理与化学性能。主要内容如下:1.使用烯丙基聚氧乙烯醚(APEE)作为PU和PA之间的偶联剂,合成了稳定的水性聚氨酯丙烯酸(WPUA)复合乳液,其AC/PU质量比范围为45/55至70/30。通过该方法可以制备具有低成本且性能优异的WPUA复合乳液,并研究了PA用量对其性能的影响。结果表明:制备的WPUA复合乳液呈现出明显的核壳结构,PU与PA之间通过化学键结合,且WPUA分子为线性结构。复合乳液在剪切过程的初始阶段表现为剪切变稀,符合牛顿流体特征。随着PA用量的增加,乳液的粒径逐渐增加并且分布变宽,乳液黏度逐渐减少,胶膜的拉伸应力、邵氏A硬度、储能模量、玻璃转化温度、耐水性和水接触角增加。2.使用聚二甲基硅氧烷(PDMS)作为混合软段引入PU分子链段当中,然后与甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)通过原位乳液共聚法制备一系列有机硅改性WPUA复合乳液,并研究PDMS用量对复合乳液及胶膜性能的影响。结果表明:乳液均显示出剪切变稀行为,随着PDMS含量的增加,乳液平均粒径增加,粘度逐渐降低。索氏提取的结果表明,WPUA共聚物为交联结构,但随着PDMS含量的增加,交联度降低。FT-IR分峰研究表明,引入PDMS降低WPUA体系的氢键含量,并增加相分离程度。PDMS含量的增加导致膜的拉伸强度,硬度,储能模量和玻璃化转变温度降低,但是断裂伸长率增加。增加PDMS含量使复合膜的水接触角显著增加,极大地改善了复合膜的表面疏水性。3.使用甲基丙烯酸十二氟庚酯(DFMA)作为丙烯酸酯单体与含硅PU预聚体进行乳液共聚,制备一系列有机氟硅改性WPUA复合乳液,研究其对复合乳液及胶膜性能的影响。所有合成乳液均显示出剪切变稀行为,随着FDMA含量的增加,乳液平均粒径而增加,乳液的粘度逐渐降低。FT-IR分峰研究表明,引入FDMA降低WPUA体系的氢键含量,并增加相分离程度。FDMA含量的增加导致膜的拉伸强度,硬度,储能模量和玻璃化转变温度降低,但是断裂伸长率增加。FDMA的引入使得复合膜的水接触角显著增加,极大地改善了膜的表面疏水性。
[Abstract]:Waterborne polyurethane acrylate (WPUA) has the advantages of polyurethane (PUU) and polyacrylate (PAA). It has the advantages of safety, environmental protection, low price, good film forming performance, excellent physical and mechanical properties, and has been widely used in the fields of paint, adhesive, textile printing and dyeing and so on. However, in the synthesis of WPUA, the content of WPU with carboxyl group as self-emulsifier is difficult to exceed 40%, and the preparation cost is high, and the hydrophilic carboxyl group on the molecular chain has poor water resistance. In order to solve these problems, isophorone diisocyanate (IPDIN) was used to synthesize isocyanate terminated polyurethane prepolymer, which was further sealed by hydroxyl vinyl compound. A polymerizable WPU prepolymer emulsion was synthesized by neutralization and emulsification. The WPUA composite emulsion with high PA/PU ratio, organic silicon modification and organosilicon fluorine co-modification was synthesized by polymerization with acrylic ester. The physical and chemical properties of the emulsion were studied. The main content is as follows: 1. Using allyl polyoxyethylene ether (APEE) as the coupling agent between pu and PA, a stable waterborne polyurethane acrylic acid (WPA) composite emulsion was synthesized. The AC/PU mass ratio of the emulsion was 45 / 55 to 70 / 30. The WPUA composite emulsion with low cost and excellent performance can be prepared by this method, and the effect of PA content on its properties is studied. The results show that the prepared WPUA composite emulsion exhibits obvious core-shell structure and chemical bonding between pu and PA, and the WPUA molecule is linear. The composite emulsion shows shearing thinning in the initial stage of shear process, which accords with the characteristics of Newtonian fluid. With the increase of PA content, the particle size of emulsion increased and the distribution became wider, the viscosity of emulsion gradually decreased, the tensile stress of the film, Shao's A hardness, storage modulus, glass conversion temperature, water resistance and water contact angle increased by 0.2. Polydimethylsiloxane (PDMS) was used as the mixed soft segment to introduce pu molecular chain into the chain, and then a series of silicone modified WPUA composite emulsions were prepared by in situ emulsion copolymerization with methyl methacrylate (MMA) and butyl acrylate (BA). The effect of PDMS content on the properties of composite emulsion and film was studied. The results showed that all the emulsions showed shear thinning behavior. With the increase of PDMS content, the average particle size increased and the viscosity decreased gradually. The results of Soxhlet extraction showed that the copolymers were crosslinked, but with the increase of PDMS content, the crosslinking degree decreased. FT-IR showed that the introduction of PDMS reduced the hydrogen bond content of WPUA system. The tensile strength, hardness, storage modulus and glass transition temperature decreased, but elongation at break increased with the increase of phase separation degree and PDMS content. The water contact angle of the composite membrane increased significantly with the increase of PDMS content, which greatly improved the hydrophobicity of the composite membrane. A series of organofluorosilicon modified WPUA composite emulsions were prepared by emulsion copolymerization of dodecyl heptyl methacrylate (DFMA) as acrylate monomer and pu prepolymer containing silicon. The effects of these emulsions on the properties of composite emulsion and film were studied. All the synthesized emulsions showed shear thinning behavior. With the increase of FDMA content, the average particle size of the emulsion increased, and the viscosity of the emulsion gradually decreased. The peak value of FT-IR showed that the introduction of FDMA reduced the hydrogen bond content of WPUA system. The tensile strength, hardness, storage modulus and glass transition temperature decreased with the increase of phase separation degree. However, the water contact angle increased with the increase of elongation at break. The surface hydrophobicity of the film is greatly improved.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ316.334

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