Pectin as a non-toxic crosslinker for durable and water-resistant biopolymer-based membranes with improved mechanical and functional properties

Biopolymer-based hydrophilic membranes with very high stability in aqueous systems were developed by using pectin as a non-toxic crosslinker. The unique properties of pectin as an efficient crosslinker were demonstrated using poly(vinyl alcohol) as a model for a highly water-soluble biopolymer. The chemical crosslinking strategy using glutaraldhehyde has proven successful in improving the stability of poly(vinyl alcohol) membranes. However, the use of non-toxic biological crosslinking agents has not been fully explored. We hypothesized that pectin, as a biopolymer bearing numerous carboxyl groups, could be a very efficient crosslinker compared to carboxylic acids, promoting unprecedented membrane stability. A systematic characterization of the chemical, thermal, mechanical, and functional properties of membranes prepared from poly(vinyl alcohol) crosslinked with pectin confirmed the excellent stability of the membranes in water, tested at the boiling point and at acidic and basic pH. The use of pectin also resulted in membranes with very high tensile strength, resistance to microbial degradation, antiradical and antibacterial activity, and improved water vapor barrier properties.