Evaluation of polyurethane/nylon 6(3) blend membranes for enhanced CO2 separation. Issue 34 (18th July 2022)

• Record Type: Journal Article
• Authors: Kiani, Sahar; Raisi, Ahmadreza
• Is Part Of: Journal of applied polymer science. Volume 139:Issue 34(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-18
• Subjects: blends -- membranes -- separation techniques; Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.52812
• Languages: English
• ISSNs: 0021-8995

Abstract

Abstract: In this study, the polyurethane (PU)/nylon 6(3) blend membranes were developed for gas separation applications, and influence of blending Nylon 6(3) in PU on the microstructure, and separation performance of the blend membranes was investigated. The PU was synthesized via a two‐step polymerization technique. The blend membranes were characterized by SEM, DSC, XRD, and FTIR analysis. The SEM results showed that the blend membranes containing 20 wt% or less nylon 6(3) had less interaction than those containing higher nylon 6(3) contents. At 50 wt% of nylon 6(3), the compatibility between two polymers and reducing CO2 permeability was observed. The blending of nylon 6(3) into the PU matrix decreased the chain mobility of the membrane, increased the membrane crystallinity, and led to a rough microstructure. The neat PU and nylon 6(3) membranes had the CO2 /N2 selectivity of 43.1 and 14.2, respectively, while the PU60/PA40 blend membrane had the CO2/N2 selectivity of 61.9. The PU50/PA50 blend showed the highest selectivity (22.4) for CO2/CH4 separation. The CO2, CH4, and N2 permeabilities in all membranes were enhanced by increasing upstream pressure. Abstract : Polymer blends have been interested in developing membranes with desirable separation performance. High‐performance polymeric membranes have developed by blending PA in PU matrix for gas separation. Decrease in permeability of gases was observed by the addition of PA due to the rigidity of PA chains. Additionally, the selectivity of blend membranes enhanced by blending PA, which shows improved selectivity over pure PU membranes.