Plasticizer-free flexible oxygen barrier films and laminates based on negatively charged and acetylated non-cellulosic polysaccharides isolated from biomass

摘要

Food, consumer, and industrial product packaging materials are provided by embodiments of the present invention. Films and laminates based on a combination of negatively charged polysaccharides are provided as such packaging materials. The films can be prepared by mildly treating soft wood with steam followed by alkali extraction and enzymatic treatment. Negatively charged non-cellulosic polysaccharides are isolated with weight average molecular weight Mw higher than 10,000 g/mol and molecular structure comprising a xylan main chain substituted with more than 15 molar % of glucuronic acid and more than 5 molar % arabinose. The negatively charged non-cellulosic polysaccharides can be casted from water solution on a suitable carrier and surface acetylated or coated with acetylated polysaccharide to obtain oxygen and water barrier packaging laminate. Inventive packaging materials can have strength at break above 55 MPa, elongation to break above 2.5%, cohesive and adhesive properties and good oxygen and moisture barrier properties.