Chitosan as Reinforcement for Biopolymers - A Mini Review

Abstract

It is nowadays urgent to find new packaging solutions that have a lower impact on the environment. Biopolymers (PLA, starch, PBAT) seem interesting to the design of the new packaging generation. These polymers have some drawbacks such as mechanical and barrier properties. Also, it could be interesting to add antimicrobial properties to packaging to increase the shelf life of food products. For those reasons, chitosan seems to be an interesting component to add to a biopolymer matrix. Chitosan is a polysaccharide derived from crustacean shells. Chitosan can be directly added to the matrix via thermomechanical processes, or it can be turned into thermoplastic chitosan with the combined effect of an acid solution, a plasticizer, heat, and shear. The chitosan intramolecular bonds are thus reduced. The second method seems to limit the agglomeration of chitosan in the polymer matrix and increase interfacial adhesion. The composite properties depend on the acid and plasticizer type and rate.