丙烯酰胺接枝聚丙烯多孔膜及其水解后的性能

摘要

Porous polypropylene(PP)membrane was modified by grafting acrylamide onto its surface to improve its hydrophilicity. The effect of nitric acid concentration, grafting time and hydrolysis time on structure and performance of the membranes were investigated. The grafting degree first increased and then decreased, while the water contact angle first decreased and then increased with the increase of nitric acid concentration. The grafting degree first increased and then tended to be constant, while the water contact angle first decreased and then tended to be constant with the extension of grafting time. The grafting degree was almost a constant and the water contact angle first decreased and then tended to be constant with the increase of hydrolysis time. The grafting degree was 1 147 µg/cm2 and the water contact angle decreased from 124°to 47°under the optimal hy-drophilic modification conditions. When the trans-membrane pressure was 0.5 MPa, the pure water flux and re-tention rate to Na2SO4 solution of 1 g/L of polyimide/PP nanofiltration membrane reached 11.89 L/(m2·h) and 92.86%, respectively.%采用丙烯酰胺接枝法对聚丙烯（PP）多孔膜表面进行亲水化改性，考察了硝酸浓度、接枝时间以及水解时间对膜结构和性能的影响。随硝酸浓度增加，接枝度先增后降，膜表面的水接触角先减小后增大；随接枝时间延长，接枝度先增加后几乎不变，水接触角先减小后趋于恒定；随水解时间延长，接枝度几乎不变，而水接触角先减小后趋于恒定。优选的亲水化改性条件下，PP多孔膜的接枝度为1 147 µg/cm2，水接触角由124°降至47°。过膜压差为0.5 MPa时，聚酰亚胺/PP纳滤复合膜的纯水通量和对1 g/L的Na2SO4溶液的截留率分别可达11.89 L/（ m2·h）和92.86%。