The preparation and performance characteristics of polyvinyl chloride-co-vinyl acetate modified membranes

摘要

The chemical modification method was used to improve the hydrophilicity of polyvinyl chloride-vinyl acetate copolymer ( VC-co-VAc ). The experimental results showed that the polymer material VC-co-VAc-OH can be obtained by hydroxy modification from VC-co-VAc. Then the polymer of VC-co-VAc-OH was used to prepare asymmetric flat-sheet membranes with the solvent of dimethyl acetamide ( DMAc) and the additive of polyethylene glycol 20000 (PEG 20000 ) by using phase inversion technique. When the polymer concentration was 16 wt.%, mass ratio of solvent to additive was 10:1, coagulation temperature was 20 °C, evaporation time was 30 s and relative humidity was 50 %, a membrane with good performance could be prepared. These results were supported by experimental data of pure water flux, retention, water content and pore size distribution.