Cationic modified bamboo powder as a reinforcing additive for improving the ring crush index of paper-based products

Enhancing the ring crush index of paper and pulp molding products has long presented a challenge in the papermaking industry. In this study, (3-chloro-2-hydroxypropyl) trimethylammonium chloride was used to conduct cationic modification on bamboo powder. The positively charged quaternary ammonium groups were covalently grafted onto the bamboo powder. This cationic modified bamboo powder can be used as a reinforcing additive, which can simultaneously enhance the ring crush and tensile strength of the paper. The cationic modified bamboo powder increased the ring crush index of the paper to 16.52 N·m·g−1, representing a 315.08% improvement over the original paper, while the tensile strength reached 31.08 N·m·g−1, corresponding to a 185.40% enhancement. Furthermore, at an additive loading of 25%, the burst strength and tear strength increased by 139.76% and 188%, respectively, relative to the original paper. The cationic modified bamboo powder was subsequently applied to pulp molding products, where it also produced significant improvements in multiple physical properties. This work demonstrates a viable strategy for preparing bio-based reinforcing additives from natural materials, offering a promising pathway for advancing the high-value utilization of bamboo resources and supporting sustainable paper-based alternatives to plastics.