紫外辐射改性聚乙烯膜的亲水性研究

Investigation of hydrophilic modified polyethylene membrane induced by UV-irradiation grafting

以低密度聚乙烯(LDPE)膜为基体,通过紫外辐射方法接枝丙烯酸(AA),制得不同接枝率的LDPE-g-AA亲水膜;利用红外光谱和扫描电子显微镜分析膜接枝前后组成和形貌的变化,并通过测试与水接触角、沉降时间和吸水率研究接枝后聚乙烯膜的亲水性.红外谱图表明,辐射接枝后的聚乙烯膜表面引入了大量羧基,并且羧基的量随着接枝率的增大而增加.扫描电镜照片显示,接枝后膜表面出现明显的颗粒状物质,证明AA接枝到了聚乙烯膜表面.当LDPE-g-AA接枝率大于10%时接枝聚乙烯膜表面与水接触角由原来的89°降低到30°,沉降时间由原来的无穷大降低到11 s,并且随着接枝率的继续增大,接触角与沉降时间趋于稳定;随着接枝率的增大,接枝后聚乙烯薄膜的吸水率增大.

A LDPE-g-AA hydrophilic membrane with different grafting degree is prepared by UV-irradiation grafting of acrylic acid（AA） on the low-density polyethylene（LDPE） membrane.The hydrophilic membrane is characterized by attenuated total reflectance Fourier transform infrared spectroscopy（FTIR-ATR） and scanning electronic microscope（SEM）.The hydrophilicity is determined by contact angle of water,settling time and water absorption.The infrared spectrum shows that the carboxylic groups are introduced into the membrane and increase with grafting degrec.SEM images reveal that the graft polymer chains grow into regular spheroidal particles on the LDPE surface.When the grafting degree of LDPE-g-AA is above of 22%,the contact angle of water on LDPE-g-AA membrane decreases from 89° to 30°,settling time decreases from infinite to 11 s.And the contact angle of water and settling time are tended to be stable.Finally,the result of water absorption shows that water absorption increases with grafting degree of LDPE-g-AA.