All-natural and high-performance structural material based on lignin-reinforced cellulose

Sustainable materials derived from lignocellulosic resources are attractive alternatives to ubiquitous petrochemical plastics. However, it remains a huge challenge to improve the mechanical properties of lignocellulosic materials through efficient and low-energy processing strategy. Herein, we report a facile lignin-reinforced cellulose strategy to manufacture an all-natural and high-performance structural material from bamboo particles via partial delignification followed by hot-pressing. Partial delignification can regulate the amount of lignin in the bamboo particles and release internal cellulose microfibers. The subsequent hot-pressing drives residual lignin into the cellulose matrix to form a dense structure, which acts as a polyphenolic binder to improve the performance of the structural material. The obtained lignin-reinforced cellulose plate (LRCP) demonstrates high isotropic flexural strength (∼162 MPa), which is higher than that of natural bamboo and typical petrochemical plastics. Moreover, LRCP shows outstanding toughness (∼2.58 MPa m1/2), excellent compressive strength (∼178 MPa), improved wet stability and superior flame resistance. LRCP is all-natural and eco-friendly without the need for additional chemical cross-linking reagents. We believe that this facile and cost-effective strategy provides a promising way to process lignocellulosic resources into all-natural and high-performance structural materials that can serve as powerful plastic alternatives in the future.