Inorganic matter modified water-based copolymer prepared by chitosan-starch-CMC-Na-PVAL as an environment-friendly coating material.

Inorganic matter modifications were used to improve the hydrophobic properties and slow-release effects of water-based copolymer films. Water-based copolymers were prepared by aqueous polymerization of polyvinyl alcohol, starch, chitosan, and sodium carboxymethyl cellulose, and then, zeolite powder, volcanic ash or biochar were added to prepare the inorganic matter modified water-based copolymer films. The results showed that the inorganic matter modified water-based copolymer films had enhanced thermal stability, reductions in O-H and water vapour permeability, and increased crystallinity and roughness. Compared with water-based copolymer films, the water absorption capacities of the zeolite powder modified water-based copolymer films, volcanic ash modified water-based copolymer films, and biochar modified water-based copolymer films were reduced by 42.8 %, 50.0 % and 39.0 %, and their ammonium permeability was reduced by 53.0 %, 12.1 % and 1.1 %, respectively. Inorganic matter modified water-based copolymer films have properties that make them suitable for use in preparing slow-release coating materials.