【作者】 汪杰；

【导师】 熊传溪；

【作者基本信息】 武汉理工大学 ， 材料学， 2012， 硕士

【摘要】 聚对苯二甲酸乙二醇酯(PET)薄膜具有良好的加工性、耐候性、透光性和优异的力学性能,在包装材料和太阳能电池背板领域有着广泛应用。氟碳树脂因其较好的耐候性、耐化学品和自洁性而广泛应用于钢结构的长效防腐、海洋防腐及防污、建筑外装饰及太阳能电池背板领域。本文选用PET薄膜为基体材料,氟碳树脂为涂层,通过表面涂覆的方式,将氟碳树脂涂覆于PET薄膜表面,以此制备出高透光率、耐候性好的涂层薄膜。同时,通过硅烷偶联剂及类流体技术对纳米Si02进行表面改性,并将其用于氟碳树脂的填充,由此来制备具有疏水性、较好透光率和耐候性的PET/改性Si02填充氟碳树脂复合涂层。论文的主要研究结果如下：(1)不同氟碳树脂含量的薄膜涂层,其透射率、水接触角、拉伸强度和断裂伸长率均随氟碳树脂含量的增加出现先增加后减小的趋势,当氟碳树脂含量为50wt%时有最大值。此时氟碳树脂在PET薄膜表面成膜性最好,能够形成均匀、致密的涂层。常规性能测试表明,不同氟碳树脂含量薄膜涂层的硬度均达2H,涂层附着力均达到1级,薄膜涂层具有较好的耐酸、耐碱及耐水性能,且经碱液腐蚀后,薄膜涂层仍保持有较高的透射率。(2)经硅烷偶联剂KH550改性的Si02粒子在氟碳树脂基体中出现较为明显的团聚,复合薄膜涂层的透射率、拉伸强度和断裂伸长率均随改性Si02含量的增加而出现下降。由于改性Si02粒子的部分团聚,在氟碳树脂基体表面形成了类似微纳米粗糙结构,改性Si02粒子的加入极大提高了复合薄膜涂层的疏水性,当改性Si02含量为0.5wt%时,其水接触角达最大值115°,较未添加改性Si02的复合涂层要高27°。添加不同含量改性Si02制备复合薄膜涂层的硬度均达2H,附着力达1级；复合薄膜涂层的耐酸、耐碱和耐水性能优良。SEM观察发现,经碱液腐蚀后的复合薄膜涂层表面出现Si02粒子的脱落现象,且其透射率在改性Si02含量较少时变化不大,在改性Si02含量较高时出现较大幅度的下降。(3)通过离子交换反应制备出具有类液体行为的Si02类流体,其化学性质稳定,且呈现单分散状态。Si02类流体的加入对复合薄膜涂层起到了一定的增透和疏水作用。添加不同含量Si02类流体制备复合薄膜涂层的透射率、水接触角、拉伸强度和断裂伸长率均出现不同幅度的增大,当Si02类流体的含量为0.2wt%时,复合薄膜涂层的水接触角达101°,较未添加Si02类流体的复合薄膜涂层增加了13°。添加不同含量Si02类流体制备复合薄膜涂层的硬度均达2H,附着力达1级。复合薄膜涂层具有优良的耐酸、耐碱和耐水性能。经碱液腐蚀后的复合薄膜涂层,其表面出现少许Si02粒子脱落的现象,但其仍保持较高的透射率。更多还原

【Abstract】 The polyethylene terephthalate (PET) film is widely used in packing materials and solar cells backplane materials due to its excellent processability, weather resisting property and good light transmittance. Fluorocarbon resin is applied in the field of long-lasting, heavy anti-corrosion for steel structure, marine anti-corrosion, decoration for external walls and solar cell backplane due to its outstanding performance regarding fine weather resisting property, chemical resistance property and self-cleaning property.In this paper, the composite coating films with the good properties of high transmittance and fine weather resisting property were successfully prepared by using PET film as the substrate depositing with the fluorocarbon resin on the surface of the PET film. At the meantime, the new methods of using silane coupler and liquidlike fluids were employed to modify SiO2. Then, the modified SiO2was filled into the fluorocarbon resin to prepare the composite coating of PET/modified SiO2FEVE with high transmittance, hydrophobicity and fine weather resisting property. The main results were displayed as follow:(1) The results of transmittance, water contact angle, tensile strength and elongation at break show the same trend that they increase firstly, and then decrease with the increasing fluorocarbon resin content. The optimal performances of the coating layer are achieved at the fluorocarbon resin content50wt%. Because at that content, the coating possesses well film forming property and can form a homogeneous and dense layer on the surface of PET film. The conventional evaluations on performances show that all the samples have the hardness of2H and the adhesion of1grade. The coated films perform good acid, alkali and water resistance. And after alkali corrosion, the coated films still show high transmittance.(2) The SiO2modified by KH550shows agglomeration in the fluorocarbon resin matrix, which leads to the decrease of the transmittance and tensile strength and elongation at break of the coated film. But the addition of modified SiO2forms a kind of micro-nano structure on the surface of the PET film and it improves the water contact angle largely. When the content of modified SiO2is0.5wt%, the water contact angle achieves the maximum of115°. The coated films prepared with different content of modified SiO2possess excellent acid, alkali and water resistance properties, and the hardness reaches2H and the adhesion reaches1grade. The SEM images show that the modified SiO2fall off the surface after alkali corrosion, but it does not affect the transmittance of the films much when the content of modified SiO2is very low.(3) Solvent-free SiO2nanofluids is prepared via ion exchange reaction process, and shows good chemical stability and monodispersity. The solvent-free SiO2nanofluids plays a role of enhancity the anti-reflective and hydrophobic properties of the composite coating layer. The transmittance, water contact angle, tensile strength and elongation at break increase due to the addition of solvent-free SiO2nanofluids. When the content of solvent-free SiO2nanofluids is0.2wt%, the water contact angle reaches101°. The hardness and adhesive force of the composite film made by adding different content of solvent-free SiO2nanofluids are still2H and1grade. The composite films also have excellent acid, alkali and water resistance properties. After alkali corrosion, only a few SiO2particles fall off the surface and the composite films remain high transmittance.更多还原