On the Pervaporation Performance of a Crystalline Polymer: Effect of the Variation of Crystallinity

Abstract

Using poly(4-methyl-pentene-1) as a separation membrane and chloro-hydrocarbon/water mixtures as the separation systems, the effect of crystallinity on the pervaporation properties was investigated. Because of the permeant–membrane interaction, a small change of organic concentration in the feed may cause the disruption of the crystallites and lead to different pervaporation performance. Three typical kinds of separation performance were identified. All the experimental results were explained by two basic reasons: (1) crystallites can prevent small molecules from permeation; and (2) crystallites can act as cross-links and prevent the swelling of amorphous regions.

Keywords:

• Poly(4-methyl-pentene-1)
• Membrane separation
• Pervaporation
• Crystallinity

Acknowledgments

This project was supported by the National Natural Science Foundation of China (no. 59833120). The authors also thank Professor Deyan Shen for his helpful suggestion on IR experiments.