两亲性PP-g-(NVP-co-PEGMA)抗污染改性剂的制备及改性聚丙烯亲水微孔膜的表征

Preparation of Amphiphilic Antifouling Modifier PP-g-(NVP-co-PEGMA) and Characterization of Modified Hydrophilic Polypropylene Microporous Membrane

以乙烯基吡咯烷酮(NVP)和聚乙二醇甲基丙烯酸酯(PEGMA)为共聚单体,采用熔融接枝法制备了两亲性改性剂PP-g-(NVP-co-PEGMA);利用红外光谱、X射线光电子能谱对制得的改性剂进行表征,研究了PEGMA单体用量对熔融接枝聚合PVP接枝率的影响。利用熔融共混和拉伸成孔工艺制备了聚丙烯亲水微孔膜。利用接触角、热失重分析、扫描电镜和水通量测试对改性剂及膜性能进行表征。结果表明,亲水性支链成功接枝到PP大分子链上,少量PEGMA的加入提高了NVP的接枝率,相比NVP作为唯一单体的情况提高了5.66%;改性PP微孔膜的热稳定性能提高,亲水性也得到很大改善,起始接触角从96.0°下降到57.5°。膜的平均孔径在0.15μm左右,孔径分布相对均匀,孔隙率为32.7%。改性后的PP膜水通量随时间的延长下降缓慢,亲水性和抗污染性能得到大幅度提高。

An amphiphilic modifier PP-g-POly [ vinylpyrrolidone-co-poly （ethylene glycol） methacrylate] was prepared by melt graft polymerization using NVP and PEGMA as copolymer monomer, dicumyl peroxide as initiator. The obtained amphiphilic modifier was characterized by FT-IR, XPS and elements analysis, and the effect of used amount of PEGMA on the grafting degree （GD） of polyvinylpyrrolidone （PVP） was investigated. Results show that the hydrophilic branched chains are grafted onto PP macromolecular chains successfully; the GD of PVP is increased to 21.36% when the mass ratio of PP/NVP/PEGMA is 100/30/15. Hydrophilic polypropylene microporous membranes were prepared via melt blending of PP and amphiphilic modifier firstly, and then by stretching. The properties of membranes were characterized by contact angle measurement, TGA, FESEM and the water flux testing. Experimental results show that the hydrophilicity of obtained modified PP microporous membrane is significantly improved. The thermal stability of modified PP microporous membrane is improved too. The initial contact angle decreases from 96.0° to 57.5°. The distribution of pores for modified membrane is relatively homogeneous The average pore size is about 0. 15 μm and the porosity is 32.7%. Compared with pure PP membrane, the water flux is declined more slowly with time. The hydrophilicity and antifouling per^orrnance of PP membrane are greatly improved.