Development of Bio-based Membranes for Building Envelope Applications from Poly(lactic acid) and Cellulose Microfibers

Abstract

A bio-based membrane was developed for building envelope applications. Biocomposites with enhanced water vapor permeability were fabricated based on poly(lactic acid) (PLA) and cellulose microfibers (CMF). To improve the interfacial adhesion between PLA and fibers, polyethylene glycol (PEG) was used as a compatibilizer for the modification of CMF. The properties of prepared PLA-based biocomposites were investigated in terms of their morphology, thermal stability, thermomechanical properties, and water vapor permeability. The morphological investigation showed the improved dispersion of cellulose fibers in the PLA matrix after modification of the bio-filler with PEG. The thermogravimetric analysis illustrated that the addition of modified CMFs increased the thermal stability of materials. Moreover, the water vapor permeability of PLA-based biocomposites was enhanced by adding modified CMFs to the PLA matrix. The results suggest that the utilization of PEG as a biopolymer compatibilizer represents a cost-effective and environmentally friendly method to improve the properties of PLA/CMF biocomposites. The developed membranes are potential materials for the fabrication of bio-based membranes with permeable properties that facilitate the transmission of entrapped water vapor through the building, eventually prolonging the service life of building envelope materials.