紫外光固化PUA/纳米SiO2杂化涂层的制备与性能

摘要

采用γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)对硅溶胶改性,将改性的硅溶胶与聚氨酯丙烯酸酯(PUA)低聚物共混,制备出聚碳酸酯(PC)用紫外光(UV)固化耐磨涂层.用红外光谱仪、热重分析仪、激光粒度仪、接触角测量仪对改性前后的纳米二氧化硅(SiO2)进行了分析表征,并对制备的UV固化涂层的透光率、雾度、表面硬度和附着力进行了测试.结果表明:纳米SiO2表面接枝上了KH-570,且亲水性降低.当KH-570用量为60％、改性纳米SiO2用量为4％时,涂覆UV固化涂层的PC的耐磨性得到最佳改善,耐磨试验后,涂覆添加4％改性纳米SiO2的UV固化涂层的PC较涂覆未添加纳米SiO2的UV固化涂层的PC,透光率降低值从4.5％降至1.1％,雾度增加值从21.29％降至3.41％,PC表面涂层的铅笔硬度达到2H.%A UV-cured coating for polycarbonate was prepared by blending polyurethane acrylate oligomers with silica sol modified by γ-methacryloxypropyltrimethoxysilane (KH-570).The silica sol was characterized by Fourier transform infrared spectrometer (FT-IR),thermogravimetric analyzer (TGA),laser particle analyzer and contact angle tester.In addition,the transmittance,haze,hardness and adhesion of the UV-cured coating were tested.The results showed that KH-570 was grafted onto the surface of nano-SiO2,and the hydrophilicity of the modified nano-SiO2 was decreased.When the addition of KH-570 was 60％ and the modified nano-SiO2 content was 4％,the scratch resistant property of PC sheet coated with UV-cured coating improved markedly.Compared with the PC sheet coated with coating without nano-SiO2,the coating comprising 4％ of the modified nano-SiO2 after scratch test exhibited the decrease rate of light transmittance decreased from 4.5％ to 1.1％,the increase rate of haze decreased from 21.29％ to 3.41％.The pencil hardness of the UV-cured coating on polycarbonate reached the level of 2H.