纳米TiO2和紫外线吸收剂对丙烯酸酯涂层抗光氧化性能的影响

讨论了锐钛矿型和金红石型纳米TiO2以及2．4-二羟基二苯甲酮和2-(2-二羟基-5-苯甲基)苯并三唑等有机紫外线吸收剂的光活性．并借助失重分析和SEM分析探讨它们对丙烯酸复合涂层抗光氧化性能的影响。UV分析表明：2，4-二羟基二苯甲酮、2-(2-二羟基-5-苯甲基)苯并三唑等有机紫外线吸收剂对400nm以下的紫外线有强烈的吸收作用；金红石和锐钛矿型纳米TiO2对紫外线也有较强烈的吸收和散射作用，紫外光透过率低。且有机紫外线吸收剂随着辐射时间的延长会分解失效，而纳米TiO2较稳定。失重分析和SEM分析结果显示：锐钛矿型纳米TiO2具有光催化性，加速丙烯酸酯聚合物的光降解，而金红石型纳米TiO2则是一种有效的遮光剂。同时添加金红石型纳米TiO2和有机紫外线吸收剂能更有效提高丙烯酸酯复合涂层的抗光氧化性能。

Effects of nanoparticle titanium dioxide and ultraviolet absorbers on anti-photooxidation of acrylic coatings

The photochemical activities of anatase and rutile titanium dioxide have been determined and compared with typical benzophenone and benzotriazole ultraviolet light stabilizers. Their performances on anti-photooxidation of water based acrylic coatings were assessed by mass loss and SEM. UV analysis shows 2,4-dihydroxybenzophenone and 2-(2-dihydroxy-5-benzyl)benzotriazole absorb strongly in the near UV below 400nm. Anatase and rutile absorb and disperse UV light, and their transmittances of ultraviolet light are low. Organic UV absorbers undergo decomposition during irradiation, whereas titania nanoparticles by virtue of their inorganic nature were inherently stable. Mass loss experiments and SEM indicate that anatase was a photosensitiser, which accelerates light degradation of acrylic resin, while rutile was an effective opacifier. Addition of both rutile and organic UV absorbers in acrylic coatings was found to be more effective.