Bamboo Self-Bonding Composites with Superior Water Resistance and Mechanical Performance Prepared with High-Consistency Mechano-Enzymatic Pretreated Bamboo Powders

The development of bamboo self-bonding composites (BSBC) has gained growing momentum due to its formaldehyde-free nature and environmental friendliness. However, the inferior mechanical properties and poor water resistance of BSBC have hindered their practical applications. Here, we manufactured BSBC using bamboo processing residue powders as raw materials through high-consistency mechano-enzymatic (HCME) pretreatment, followed by hot pressing. Microscopic examination revealed that HCME pretreatment facilitated bamboo fiber defibrillation, generating subfibrous branches and fragmented parenchyma cells with increased specific surface areas. The mechanical interlocking structure enabled BSBC to achieve a combination of mechanical reinforcement and densification. After 8 h of HCME pretreatment, the porosity of BSBC was only 3.27%, which was 57.1% lower than that without pretreatment. BSBC also demonstrated superior water resistance and mechanical performance. It exhibited a low thickness swelling rate (5.1%), which is a 50.5% reduction compared with BSBC manufactured without HCME pretreatment. Moreover, BSBC exhibited high flexural strength (37.8 MPa) and high internal bonding strength (1.84 MPa) after 8 h of HCME pretreatment, significantly surpassing the industry standard for furniture-grade medium-density fiberboards. Environmentally friendly BSBC, based on HCME pretreatment, is anticipated to be a promising alternative to traditional fiberboards in the furniture industry.