Biodegradable gas separation membrane preparation by manipulation of casting parameters

Abstract

Poly(lactic acid) PLA that derived from renewable resources can help our society to reduce the dependence to non-renewable fossil resources. When come to human contact, this polymer and its degradation product are neither toxic nor carcinogenic to human body. The use of poly(lactic acid) (PLA), a biodegradable polymer, as a membrane material would assist the reduction of depending to petroleum-based polymer that will assist in disposal issues on non-biodegradable polymer. This study investigated the effect of evaporation time to the gas separation performance of PLA membrane. Membrane prepared from polymer solution consists of PLA and dichloromethane (DCM) as solvent was fabricated using pneumatically controlled casting system with dry/wet phase inversion method. Permeation test was conducted using pure oxygen and nitrogen gas. The results revealed that as the evaporation time increased, the pore size and surface porosity decreased, while the skin layer thickness increased. Although the morphology of the prepared membranes showed the desirable structure, the gas separation performance of the membrane prepared with polymer concentration of 15 wt% and 60s evaporation time was found to be promising but not yet commercially ready.