超高分子量聚乙烯微孔膜的亲水性改性研究

Hydrophilic modification of UHMWPE microporous menbrane

采用与聚乙二醇(PEG20000)共混的方法来改善UHMWPE微孔膜的亲水性,研究了改性剂含量对膜结构、亲水性能、渗透性能及力学性能的影响。结果表明:改性后UHMWPE微孔膜的孔结构有所增大;随着改性剂含量的增加,膜的亲水性大致呈上升趋势,但由于部分PEG20000会溶于蒸馏水,随着水洗时间的延长,改性剂发生流失,膜的亲水性发生衰减;相较于改性前,改性膜的水通量、蛋白质通量及纯水恢复量均显著上升,意味着膜具有很好的渗透性及抗蛋白质污染性;当PEG20000的质量分数为15%时,改性剂与UHMWPE的相容状态达到最佳结晶度显著增大,且聚合物分子链互相缠结起到物理交联作用,膜的力学强度可提高至15MPa左右。

Hydrophilic UHMWPE membranes could be obtained by blending with PEG20000and the structure,hydrophilicity,permeability and mechanical properties of modified films were investigated.It was found that the pore structure of the membranes increased.With increase in modifier content,the hydrophilicity of films showed ascendant trend in general.However,the attenuation of hydrophilicity would occur due to the loss of PEG20000with prolongation of soaking time in water.Compared with unmodified UHMWPE films,the notable rise in pure water flux,protein flux and recovery flux all meant better water permeation and fouling resistance of UHMWPE membranes after modification.The compatibility of PEG20000and UHMWPE turned to be optimum and the crystallinity increased significantly when the modification occupied 15wt%.Meanwhile,the physical crosslinking of molecular chains between modifier and UHMWPE also contributed to improve the tensile strength of membranes to near 15MPa.