利用醇类与醛类化合物的缩醛化反应,生成枝状或网状非水溶性的亲水性大分子,以制备具有持久亲水性的聚偏氟乙烯中空纤维膜.根据溶液的浊度变化来确定交联程度.反应体系为戊二醛与聚乙烯醇(PVA)在溶剂二甲基乙酰胺中的缩醛化反应,反应温度为70℃,反应时间30min,催化剂为盐酸(质量分数36.59/6).改性后的聚偏氟乙烯(PVDF)分离膜的亲水性、水通量明显提高,蛋白吸附性降低,有较好的化学稳定性.随着PVA浓度的增加,膜材料的接触角相应变小,亲水性能增强,蛋白吸附性降低.
Using the acetalization of alcohols and aldehydes to prepare enduring hydrophilic PVDF membrane. The reaction can produce non-water-soluble hydrophilic macromolecules with branching or network structure. According to the NTU of solution, we determine the solubility of crosslinks. The system is identified as the acetalization of glutaraldehyde with polyvinyl alcohol (PVA, 1 750±50) in the solvent DMAc. The catalyst is concentrated hydrochloric acid (36. 5 %). Reaction temperature is 70 ℃ and reaction time is 30 rain. Modifications of PVDF membrane significantly increase hydrophilicity and water flux, decrease protein adsorption and have better chemical stability. The contact angle and the protein adsorption of the membrane material are reduced while the hydrophilic performance enhanced with the increasing of PVA concentration.