Vapor barrier membranes based on polylactic acid and cellulose microfibers for the building envelope application

Abstract

Abstract This study aims to develop a fully bio-based barrier membrane from polylactic acid (PLA) and cellulose microfibers (CMF) to control the transmission of water vapor through building envelopes that could otherwise lead to moisture accumulation and deterioration of building materials. To improve the dispersibility of CMF in the PLA matrix, the bio-filler was modified with lactic acid (LA) by a simple esterification reaction. The contact angle test results demonstrated that the hydrophilicity of CMF reduced after the modification. Based on the morphological analysis, the LA-modified CMF (CMF-LA) showed excellent dispersion in the PLA matrix due to the improved interfacial adhesion between modified fibers and PLA. The results of thermal analyses indicated that the glass transmission temperature and thermal decomposition temperatures of materials enhanced after the addition of bio-fillers. Moreover, PLA-based composites incorporated with CMF-LA displayed superior vapor barrier properties compared to PLA/untreated CMF composites. Additionally, the environmental impact of developed membranes was studied by the life cycle assessment tool and results indicated that the incorporation of bio-fillers to PLA reduced the global warming potential. The obtained results suggest that LA-modified CMF can proceed simple, cost-effective, and sustainable to fabricate a PLA-based membrane for the building envelope application.