冻胶法制备超高分子量聚乙烯/SiO_2杂化微孔膜研究——稀释剂与SiO_2对铸膜液熔融结晶性能的影响

Preparation of ultrahigh molecular weight polyethylene (UHMWPE)/SiO_2 hybrid microporous membranes via gelation method——The effect of diluent and SiO_2 on behaviors of melting and crystallization

根据界面相分离原理,以矿物油为稀释剂,SiO2为添加剂,采用冻胶法制备了超高分子量聚乙烯(UHMWPE)膜以及UHMWPE/SiO2杂化微孔膜,讨论了稀释剂以及无机粒子含量对膜熔融结晶性能的影响。结果表明,矿物油作为微孔稀释剂,其加入使微孔膜中UHMWPE熔点降低,结晶度减小。当SiO2与UHMWPE质量比低于8/10时,随SiO2含量增加,UHMWPE熔点变化不显著,熔限增加,结晶温度升高,相对结晶度增大,微晶尺寸减小;当SiO2加入量足够大时,相对结晶度反而减小。随SiO2其含量增加,界面孔增多,膜孔隙率提高,水通量增大,泡点孔径先增大后减小。

Microporous membranes of ultra-high molecular weight polyethylene （UHMWPE） and UHMWPE/ SiO2 were prepared by gelation method, using mineral oil as diluent and SiO2 as Additives. The effect of diluent and SiO2 on behaviors of melting and crystallization was studied. The results suggested that the addition of diluent decreased the crystal density of UHMWPE,which made the melting point and crystallinity lower while the crystal size increased. With SiP2 content increasing, the melting limit widened, the crystallization temperature and crystaUinity increased,and the crystal size decreased. When the SiO2 increased further, the trend of all above results reversed. Moreover, with SiP2 increasing,the porosity and pure water flux increased resulting from interface microvoid between UHMWPE and SIP2. The bubble point pore diameter reached the max when UHWWPE/SiO2 was 10/10 （wt/wt）.