Fabrication of multifunctional PVA mulch films reinforced by hydrothermally treated corncob lignocellulose for facilitating crop growth

The severe pollution, high cost and the limited functionality constrain the agricultural mulch film extensive development. To address these issues, a low-cost, eco-friendly, and multifunctional biodegradable polyvinyl alcohol-based mulch film (PUCH) was designed with acid-hydrolyzed and hydrothermally pretreated corncob (CC) lignocellulose as reinforcing fillers, crosslinked by glutaraldehyde, urea as fertilizer, and glycerol as plasticizer. Compared with the control sample of PU-0, PUCH-20 exhibited the highest toughness, tensile strength and elongation, which increased by 92.82%, 80.54% and 51.37%, respectively. On the other hand, the PUCH mulch film also demonstrated the improved water resistance, thermal insulation performance, thermal stability and biodegradability. Furthermore, the PUCH-40 mulch film presented outstanding UV-shielding of UVC (92.1%), UVB (95.6%) and UVA (96.9%), and the thermal insulation performance was promoted by nearly 10 °C compared to the blank sample without covering film. Additionally, the PUCH mulch films showed better growth pattern compared with the commercial polyethylene mulch film. The degradation rate of PUCH-40 reached 40.10% after 100th days. These results indicate this work develops an innovative, green and efficient strategy to design high-performance degradable mulch film to promote crop growth in the field of sustainable agriculture.