Sustainable and hydrophobic polysaccharide-based mulch film with thermally stable and ultraviolet resistance performance

This work aimed to construct a polysaccharide-based mulch film with good performance for replacing plastic mulch by coating the glutaraldehyde crosslinking chitosan and humic acid/urea complexes (GCS) into cellulose/humic acid (HA/CE) film. By flow-coating with GCS to construct hierarchical networks, GCS-HA/CE film is endowed with the improved property. The influences of composition with different concentrations on mechanical properties were studied, and the optimum concentration was determined. The tensile strength and elongation of GCS-HA/CE film could reach 53.97 MPa and 12.86 % in dry state, respectively. Results suggest that glutaraldehyde crosslinking reduces moisture content, water solubility, and water vapor permeability, but increases contact angle (94.025°). Meanwhile, the thermostability and ultraviolet resistance were improved. The infrared spectroscopy and X-ray diffractometry demonstrated the successfully crosslinked by glutaraldehyde. Morphological analyses present film has excellent compatibility. In addition, GCS-HA/CE film shows good heat preservation, aging resistance, and biodegradability, indicating certain guiding significance for polysaccharide-based mulch film.