Abstract: The effects of the secondary additives on the rate of solvent evaporation and the performance of PVC UF membrane were investigated.It is found that the sort and content of secondary additives can influence on both the value of evaporation rate constant b and the membrane performances.The greater the difference between secondary additive and solvent, and the higher the content of secondary additive,the more remarkable change in the value of b.In the conditions used,the maximum flux value appears at 5%(wt)of secondary additive in the casting solution.Moreover,the evaporation time also has an important influence on the formation of polymer network pores and polymer aggregate pores,along with their size and the size distribution.

Key words: Polyvinylchloride, Ultrafiltration membrane, Property