【作者】 彭峰；

【导师】 袁继新；

【作者基本信息】 温州大学 ， 有机化学， 2011， 硕士

【摘要】 纳米杂化改性水性聚氨酯是水性聚氨酯改性的一种重要方法。在以往的研究中主要直接在聚氨酯中添加纳米粒子,而纳米粒子易于团聚,与聚氨酯的相容性较差,影响杂化材料的性能。本论文基于溶胶凝胶法的制备原理,以正硅酸乙酯（TEOS）为前躯体,以硅烷偶联剂γ-氨基丙基三乙氧基硅烷（APTES）为纳米粒子与聚氨酯的连接桥梁,制备出以化学键键合的水性聚氨酯/SiO₂有机无机杂化材料,研究不同正硅酸乙酯含量对杂化材料结构与性能的影响。本文分两种方法制备水性聚氨酯/SiO₂杂化材料。方法一是利用聚氨酯主链末端键接的APTES与TEOS直接杂化,原位生成纳米SiO₂,制备水性聚氨酯/SiO₂杂化材料,该杂化乳液具有良好的贮藏稳定性。正硅酸乙酯水解缩合制备纳米粒子,纳米粒子均匀地分布在聚氨酯基体中,没有发生明显的团聚现象,其粒径约为50nm。硅烷偶联剂将水性聚氨酯和SiO₂以化学键的形式连接起来,提高了二者之间的相容性。正硅酸乙酯的加入影响了聚氨酯的结晶性能,而且使杂化材料具有良好的耐低温性能、耐热稳定性、耐水性以及疏水性,拉伸强度增强,断裂伸长率、玻璃化温度下降。方法二基于两步法原理,以正硅酸乙酯为前躯体,盐酸为催化剂,水和无水乙醇为溶剂,制备硅溶胶。再将硅溶胶与APTES封端的聚氨酯进行混合,制备出水性聚氨酯/SiO₂有机无机杂化材料。硅溶胶的加入提高了水性聚氨酯的耐低温性能、耐热稳定性、耐水性、疏水性和拉伸强度,断裂伸长率、玻璃化温度下降。更多还原

【Abstract】 Hybridized waterborne polyurethane by nanomaterial is an important method in the modification of waterborne polyurethane. In the previous researches, nanoparticles were directly added into waterborne polyurethane, which resulted in nanoparticle’s agglomeration and incompatibility between nanoparticles and polyurethane, and influenced the properties hybrid materials. In the thesis, waterborne polyurethane/SiO₂ organic-inorganic hybrid materials based on sol-gel technology were prepared by using tetraethoxysilane（TEOS） as precursor, silane coupling agent 3-aminopropyltriethoxylsilane （APTES） as bridging agent between polyurethane and nanoparticles, respectively. Thus, nanoparticles were chemically bonded with polyurethane backbone. The effects of TEOS content on the structure and properties of hybrid materials were investigated.Waterborne polyurethane/SiO₂ organic-inorganic hybrid materials were prepared by two methods. The first one is as follows: waterborne polyurethane/SiO₂ materials were prepared by the hydrolization and condensation of TEOS or/and APTES endcapping the WPU molecular chain. The hybrid emulsions exhibit excellent storage stability. The hybrid was characterized by SEM, EDS, TEM, FTIR and XPS. The effect of TEOS on surface wettability, water resistance, mechanical strength and thermal properties of the hybrid was also evaluated by contact angle measurement, water absorption test, mechanical test, TGA and DSC, respectively. The result showed that well dispersed nano-silica in WPU was synthesized, with a typical diameter of about 50 nm. And the results indicated that the addition of nanosilica affected the crystallinity of polyurethane. Additionally, chemical interaction occurred between WPU and silica. Also, an increase in advancing contact angle, water resistance, tensile strength, thermal stability was obtained with the addition of TEOS, while elongation at break and glass transition temperature deceased,Another method was based on the principle of two-step method. Silica sol was prepared firstly with TEOS as precursor, hydrochloric acid as catalyst, water and absolute ethyl alcohol as solvent. Then waterborne polyurethane/SiO₂ organic-inorganic hybrid materials were prepared by the hybrid reaction between silica sol and polyurethane endcapped by APTES. The results indicated that the addition of silica sol into polyurethane enhanced the hybrid material’s resistance to low temperature, thermal stability, water resistance and hydrophobicity. Elongation at break and glass-transition temperature decreased.更多还原