Preparation of Plastics- and Foaming Agent-Free and Porous Bamboo Charcoal based Composites Using Sodium Silicate as Adhesives

Abstract

Plastics and foaming agents are often used to prepare large-size and low-density bamboo charcoal (BC) based composites. In this study, a plastic-free and foaming agent-free BC based composite was prepared by substituting sodium silicate (SS) for plastics. The effect of both the BC particle sizes and the usage amount of SS on the mechanical and adsorptive properties of the BC/SS composites were investigated. The experimental results show that when the BC particle size is 270 μm and the mass ratio of BC to SS is equal to 10:5, the BC/SS composite has the optimal foaming effect and best comprehensive properties. In addition, the foaming pores of the composite are caused by water vapor, which has difficulty escaping the BC because of the blockage of SS during the hot pressing process. In the BC/SS composite (10:5), the static bending intensity and the compressive strength reach respectively 6.13 MPa and 5.5 MPa, and the average pore size and porosity are 557.85 nm and 52.03%, respectively. In addition, its formaldehyde adsorptionrate reaches 21.6%. In view of good mechanical properties, formaldehyde adsorption, and environmentally friendly performance, the BC/SS composite has a great potential as a core layer of interior building materials.

Hygroscopicity and Morphology of Bio-Based Boards—The Influence of the Formulation

“…Sodium silicate, also known as "water glass", is a widely produced material, which has demonstrated several benefits. It is water-soluble, fire-resistant, non-toxic, and, hence, not dangerous to human health, environment-friendly, and economically convenient [38][39][40]. It has been employed in several sectors, such as to produce detergents and cleaning compounds [38], for material treatments [40], in ceramics [41], and in the production of geopolymers [42] and concretes [43].…”

“…It is water-soluble, fire-resistant, non-toxic, and, hence, not dangerous to human health, environment-friendly, and economically convenient [38][39][40]. It has been employed in several sectors, such as to produce detergents and cleaning compounds [38], for material treatments [40], in ceramics [41], and in the production of geopolymers [42] and concretes [43]. Among its several uses, the employment of sodium silicate as a binder to produce bio-based building composites could be a promising possibility [44].…”