摘要： 以四乙氧基硅烷 ( TEOS)作为主要前驱体, 通过改变溶胶 - 凝胶工艺参数制得了结构和形态各异的丙烯酸酯聚氨酯 /SiO2纳米复合涂层, 利用 TEM、SAXS等手段表征涂层的结构与形态, 由洗刷前后涂层的失光率来表征耐刮伤性, 详细探讨了纳米复合涂层耐刮伤性与 S iO2相特征、有机无机相作用力及 SiO2质量分数之间的关系。研究表明: 丙烯酸酯聚氨酯涂层中引入纳米 S iO2相后, 耐刮伤性明显提高。有机相与 S iO2相之间的作用力是影响涂层耐刮伤性的最重要因素, 作用力越强, 耐刮伤性越好。网络状纳米 SiO2与颗粒状纳米 S iO2相比, 更有利于耐刮伤性的提高, 且网络状纳米SiO2质量分数越大, 耐刮伤性越佳, 但 S iO2相的致密度和尺寸对耐刮伤性影响较小。对于颗粒状胶体 SiO2, 在 15~ 160 nm范围内, 粒径对耐刮伤性没有明显影响; 随着胶体 S iO2粒子的质量分数增加, 耐刮伤性先增大后减小。

关键词: 丙烯酸酯聚氨酯涂层; 耐刮伤性; 胶体二氧化硅; 纳米复合涂层; 失光率

Abstract: Acry lic based po lyurethane /silica nanocomposite coatings w ith different structure or morpho logy w ere prepared by so l- ge l process using tetraethoxysilane ( TEOS) as thema in precursor. Themorpho logy and structure of the nanocomposite coatings w ere characterized by transm ission e lectron m icroscopy ( TEM ) and sm all angle X- ray scattering ( SAXS) method, wh ile the scratch resistance by the gloss loss of the coatings film afterw ashing. The enhancemen t of nanosilica( inc lud ing phase features o f S iO2, interaction and S iO2 ratio) on the scratch resistance o f organ ic coatings w as further d iscussed in th is article. It is found that the scratch resistance of nanocomposite coatings depends rather on the in teraction betw een o rgan icmatrix and silica phase than on the character of silica phase, and moreover, the higher the interaction, the better the scratch resistance. It seems that the coatings contain ing silica netw ork show s better scratch resistancethan those conta in ing silica particles. Add itionally, the scratch resistance o f nanocomposite coatings increases firstly and then decreases w ith increasing m ass fraction o f co lloida l silica partic les but slightly increases with increasing content of silica density or particle size.

Key words: acry lic based polyurethane coatings; scratch resistance; colloidalsilica; nanocomposite coatings;gloss loss