Lignocellulosic biocomposites for preservation and storage materials based on suberin-enriched cork

Traditional wood-plastic composites (WPC) face numerous challenges in their applications, such as the lack of flexibility, cushioning performance, water barrier properties, biodegradability and recyclability. To address these issues, in this work, a recyclable lignocellulosic biocomposites with excellent comprehensive performance was developed using cork flour and poly(1,4-dioxan-2-one) (PPDO) as the green raw materials. The prepared cork/PPDO WPC contained up to 70 wt% cork flour, conferring them with enhanced flexibility (elongation at break >10 %) and cushioning performance due to the strong interactions between PPDO and cork flour, as well as the cork unique flexibility from cork cavity structure and suberin. Additionally, due to the presence of hydrophobic suberin in cork, the cork/PPDO WPC displayed low water absorption (< 2 %) and excellent water barrier properties, making it suitable for using as packaging materials of fresh products such as fruits and vegetables. Indoor natural aging tests demonstrated that the cork/PPDO WPC maintained fine mechanical properties even after 17 weeks, with PPDO hydrolysis being effectively delayed by the cork flour. Notably, the PPDO in composite could be efficiently recovered through depolymerization with very high recovery rate and monomer purity (> 99.5 %).