摘要
含氟聚合物由于良好的耐候性、抗紫外辐射性能和化学稳定性,是太阳能电池背板的关键组成材料.但由于含氟聚合物表面能低,普遍存在与封装太阳能电池组件的乙烯-醋酸乙烯酯共聚物(EVA)胶膜粘接性差的缺点.本文利用紫外光接枝技术对含氟聚合物膜进行表面改性,将丙烯酸丁酯-三羟甲基丙烷三丙烯酸酯共聚物(PBA-TMPTA)接枝在含氟聚合物表面;研究了辐照时间、单体组成和单体浓度对接枝反应的影响;对接枝前后膜表面的化学组成和表面形貌进行了表征,结果表明紫外光接枝反应能够成功地在含氟聚合物膜表面引入接枝层.PBA-TMPTA共聚物改性后的含氟聚合物与EVA胶膜层压粘接后剥离强度可达未改性膜的15倍以上(17.6N/cm),而接枝含有羟基和羧基官能团的共聚物并不能改善其粘接性能.通过模型实验推断合成PBA-TMPTA过程中未反应的双键参与了粘接界面的化学反应而形成了界面间的共价键,因此界面粘接性能的改善主要是由于化学键作用而非物理作用.
As an important part of photovoltaic(PV) modules, backsheet materials play an important role in protecting solar cell from environmental degradation caused by moisture penetration. Fluoropolymers, which have excellent weatherability, UV radiation resistance and chemical stability, are widely used as the outer layer of the backsheet to ensure the long-term reliability and safety of PV modules. However, the low surface energy and poor adhesion to other materials of fluoropolymer markedly limits its practical application in encapsulation of solar cells which require the backsheet to be firmly bonded with PV modules by ethylene-vinyl acetate copolymer(EVA) hot melt adhesive. Although some methods such as corona discharge, plasma treatment, radiation grafting can effectively improve the surface properties of fluoropolymers, UV-induced graft polymerization is still considered as one of the most promising approach due to its advantages in fast reaction rate, low cost of processing, simple equipment, easy industrialization, and no damage to bulk property of materials. In this paper, different copolymers of acrylic acid-butyl acrylate(PAA-BA) or butyl acrylate-trimethylolpropane triacrylate(PBA-TMPTA) were introduced onto fluoropolymer film by photografting polymerization. The effects of UV irradiation time, monomer composition and monomer concentration on the graft efficiency were investigated. The chemical composition, surface morphology and chemical composition of the film were characterized by attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR), scanning electron microscopy(SEM), energy-dispersive X-ray spectroscopy(EDS) and contact angle analysis(CA). The results showed that the UV-induced graft polymerization can be successfully performed on the fluoropolymer film and a dense graft layer could be introduced on the surface. The introduction of PAA-BA changed the surface property of fluoropolymer film and facilitated the spreading of EVA, while the adhesive strength of PAA-BA modified surface
作者
祁源
王印典
赵长稳
马育红
杨万泰
Yuan Qi;Yindian Wang;Changwen Zhao;Yuhong Ma;Wantai Yang(School of Materials Science and Engineering,Beijing University of Chemical Technology,Beijing 100029,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2018年第34期3623-3630,共8页
Chinese Science Bulletin
基金
国家自然科学基金(51521062)
北京市自然科学基金(2162035)资助
关键词
光接枝
表面改性
太阳能电池背板
聚偏氟乙烯
粘接
photografting
surface modification
solar cell backsheet
polyvinylidene fluoride
adhesion
