Preparation and Gas Transport Properties of CO2-Selective Poly(ether-bamide 6)/ Vinyl Acetate- Based Polymer Blend Membranes

In the present work, membranes based on the block copolymer of poly(ether-b-amide 6) (under Pebax 1657 trademark) and its blends with poly(vinyl acetate-co-dibutyl maleate) (P(VAc-co-DBM)) were prepared by solution casting method and effect of P(VAc-co-DBM) mass content (10 to 50 wt%) on the gas transport properties were studied for CO2 and CH4 gases. Results showed that the prepared membranes have been became more CO2-philic by addition of P(VAc-co-DBM) but permeability of both gases were reduced because of the significant reduction in gas diffusivity. Theoretical density measurement of blends also confirmed that gas diffusivity reduction is due to the free volume contraction. In spite of the permeability reduction, CO2/CH4 selectivity was increased remarkably. Thermal properties of blends were studied by DSC. DSC results showed that there is a phase separation in micro-scale.

Keywords:

Poly(ethylene oxide-b- amide 6) , (P(VAc-co-PA6)) , vinyl acetate- based polymer , blend films , gas transport properties