光伏胶膜专用EVA的结构与加工性能

Structure and Processing Performance of EVA for Photovoltaic Film

利用傅里叶变换红外光谱仪、差示扫描量热仪、凝胶渗透色谱仪、旋转流变仪、高压毛细流变仪等分析手段,对2种光伏胶膜专用乙烯-醋酸乙烯共聚物(EVA)样品(样品1和样品2)进行了结构与加工性能研究。结果表明:与样品2相比,样品1的醋酸乙烯(VA)含量、熔体流动速率更趋近于中心值,密度、拉伸强度、维卡软化温度、毛细流变剪切黏度高,短支链含量、小晶点数量多,相对分子质量及其分布相当,熔融温度、结晶度、长支链支化程度低。2种样品抗热氧稳定性好,在较宽的剪切速率范围内无熔体破裂,可以满足流延膜机高速挤出制膜。

The structure and processing properties of two kinds of ethylene vinyl acetate copolymer(EVA)samples(sample 1 and sample 2)for photovoltaic adhesive film were studied by means of Fourier transform infrared spectroscopy,differential scanning calorimetry,gel permeation chromatography,rotary rheometer,high pressure capillary rheometer and other analytical means.The results show that compared with sample 2,the vinyl acetate(VA)content and melt flow rate of sample 1 are closer to the center value,and sample 1 has higher density,tensile strength,Vicat softening temperature,capillary rheological shear viscosity,more short branched chains,small crystal points,similar relative molecular mass and distribution,lower melting temperature,crystallinity,branching degree of long branched chains.The two samples have good thermal oxygen resistance stability and no melt rupture within a wide range of shear rates,which can meet the requirements of high-speed extrusion film production by casting film machines.