Co-precipitated poly(vinyl alcohol)/chitosan composites with excellent mechanical properties and tunable...

The preparation of polymeric materials with high performance and functional performance remains a focus of extensive research. In this paper, a good dispersion of regenerated chitosan (RCS) in the poly(vinyl alcohol) (PVA) and a physical cross-linking network of molecular chain entanglements and hydrogen bonding were realized by unique co-precipitation to prepare composites. Dynamic mechanical analysis and tensile tests demonstrated that RCS achieved a significant increase in the mechanical properties. The storage modulus and tensile strength of composites containing 5% RCS were 5205 MPa and 105.7 MPa, which were significantly higher than the 3416 MPa and 60.2 MPa of the pure PVA. Intriguingly, the fabricated PVA/RCS composites exhibited good pH-sensitivity due to internal hydrogen bonding. Moreover, this achieved a tunable water-induced shape memory behavior at different pH environments. This study provides a promising strategy for the use of renewable polysaccharide to achieve high performance and functionality of polymer materials.