High-performance glued-bamboo through activation of chemical bonding interface

Abstract

Bamboo glue products are widely used in decoration, construction and transportation. Bamboo is fast growing, strong and inexpensive, making it one of the ideal processing materials to replace steel and wood. Here we present a process for the production of high performance bamboo glue products. In this process, the conversion of natural bamboo surface (NBS) to oxidized bamboo surface (OBS) is a critical step prior to hot pressing, as it provides the bamboo interface with active sites (aldehyde groups) for chemical cross-linking with the adhesive. Subsequent covalent crosslinking with branched chain amine (PAXN) compounds is based on Schiff base chemistry. The improved properties of the oxidized bamboo specimens were attributed to chemical cross-linking within the oxidized bamboo-binder interface (OBI-PAXN) and further densification of the bamboo adhesive interface. The dry/hot/boiling water bond strength of OBI-PA6 N was increased by 130 % (7.5 MPa)/148 % (5.05 MPa)/130 % (3.26 MPa) compared to NBI-PA6 N (3.26 MPa, 2.04 MPa, 0.88 MPa). Its bonding strength and bending strength are superior to commercial PF resins. The combination of excellent mechanical properties with the rich, renewable and sustainable nature of bamboo makes it very attractive for engineering applications.