Influence of plasticiser type and nanoclay on the properties of chitosan-based materials

Chitosan, a biocompatible polysaccharide having antimicrobial efficacy, is highly useful for biomedical and other applications. How chitosan properties can be tailored continues to attract intense research interest. Herein, chitosan/carboxymethyl cellulose (CMC) materials filled with montmorillonite (MMT) were thermomechanically processed resulting in excellent nanoclay dispersion. Inclusion of MMT significantly increased molecular relaxation temperatures, tensile mechanical properties, film surface hydrophobicity. When plasticisers such as 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) or glycerol introduced, the effect on biopolymer largely depends whether alters plasticiser–biopolymer interactions. [C2mim][OAc]-plasticised exhibited relatively high contact angle (100 ± 7°) similar un-plasticised chitosan/MMT material, derived from strong hydrogen-bonding capability [C2mim][OAc]. Polyelectrolyte complexation (PEC) allowed glycerol-plasticised chitosan/CMC material have hydrophobic (contact angle: 90 6°) that chitosan/CMC/MMT material. Specifically, further inclusion interrupted biopolymer–plasticiser interactions, leading wettability. However, while addition [C2mim][OAc] resulted reduced hydrophilicity matrix, counteracted this by interacting IL. This work shows influence mainly determining availability free polar groups.