Study of the Influence of Bamboo Suspension Water-Removal Processes on the Properties of Bamboo-Based Molding Materials

Bamboo is a fast-growing lignocellulosic plant in nature. It is an abundant and renewable resource with wide applications. The processing of bamboo results in a large amount of residue. In this paper, we developed a method to utilize bamboo residue to prepare a novel lightweight porous molding material. A hydrated thermochemical grinding process was proposed to disintegrate bamboo fibers and activate bamboo's own binding components. The influence of the water removal by pressure from bamboo suspension and subsequent different drying methods on the product's properties was evaluated. The two-step drying ensured a low production cost and high product quality. The bamboo molding material was characterized based on thermal stability, morphology, functional groups, particle size distribution, crystallinity, and mechanical strength. A lightweight porous material was obtained with a density of 0.23-0.35 g/cm³ by freeze-drying. A high mechanical strength was obtained with a tensile strength of 0.62 MPa and a compressive strength of 10.31 MPa by oven drying. The auto-adhesive mechanisms, including fiber anchorage, polymerization, water plasticization, and heat plasticization, were discussed. The bamboo molding material is a reconstruction of bamboo cell wall components and is easy to recycle. It has potential applications in construction and buildings, packaging, and indoor furnishings.