Propene/1-octene copolymers as a new pervaporative membrane material for wastewater treatment

Organophilic pervaporation is an interesting and promising membrane technology for wastewater treatment, and its topic is always to develop new membrane materials with high separation and application properties. In this study, a new polymeric membrane material-propene/1-octene copolymers (P-co-Os) were synthesized by means of slurry polymerization process under atmospheric pressure using Ziegler–Natta catalyst (MgCl2/TiCl4/AlEt3). The aim was to investigate the correlation between the copolymeric structures and properties. Results from copolymerization showed that at 50 C, when the mole ratio of Al in AlEt3 and Ti in TiCl4 was 100 and 1-octene concentration was over 0.168 mol/L, random and low-crystalline P-co-Os were obtained. They were demonstrated to have excellent thermal stability and higher mechanical strength than the generally used PDMS membrane. P-co-Os with about 24.6 mol% 1-octene content, its weight loss started at about 400 C and break strength was 1.7 MPa. Moreover, from pervaporation measurements with chloroform/water mixtures, it was found that an increase of 1-octene content in P-co-Os resulted in a decrease of glass transition temperature (Tg), and thus the higher permeate flux but lower selectivity appeared. In general, P-co-Os did exhibit prospects for organophilic pervaporation.