Promising green composites: Bamboo based/epoxy resin composite pipes with high mechanical stability designed by cascade

Abstract

Since bamboo possesses an extremely high weight-strength ratio, excellent flexibility, and a unique round structure, this fast-growing and abundant biomass has been thought of as a promising alternative to building materials, especially plastic pipes. However, the inherent limitations, including poor water resistance, transverse mechanical weaknesses, and low mildew resistance, hinder its application. Composite bamboo with resins could effectively improve the above problems, but resin modification methods that have been traditionally used fail to achieve strong interfacial bonding with the bamboo substrate, which could not meet the requirements for high performance in harsh conditions. This study treated round bamboo with limited delignification and acetylation. The limited delignification treatment promoted lateral impregnation of the epoxy resin into the round bamboo substrate and maximized retention of the performance advantages of round bamboo. The treatment also provided more reaction sites for acetylation. The acetylation treatment enhanced interfacial adhesion between the cured epoxy resin and the round bamboo substrate. Due to this tighter connection from both physical structure bonding, the as-prepared bamboo-based/epoxy resin composite pipes exhibited excellent mechanical performance, with a tensile strength of 3.89 MPa in the hoop direction, 74.69 MPa in the longitudinal direction, and a ring stiffness of 50.26 kPa. This study prepared a sustainable and high-strength candidate for plastic pipes through a low-carbon, energy-saving, and emission reduction method, which brought new perspective for achieving the goal of carbon neutrality.