Experimental study on selected properties and microstructure of pine-based wood ceramics

Abstract Wood ceramics using biomass materials as templates possess the benefits of facile fabrication and versatile applicability. To investigate the physical properties, chemical properties and microstructure of wood ceramics prepared from biomass materials, the basic properties and potential applications of wood ceramics were expounded. In this paper, wood powder wood ceramics (WPWC) and wood fiber wood ceramics (WFWC) were prepared through the vacuum carbonization method, utilizing pine powder and pine fiber as raw materials. The impact of phenolic resin concentration and mixture filling mass on various properties of wood ceramics, including mass loss rate (MLR), volume shrinkage rate (VSR), apparent porosity (AP), and bending strength (BS) were investigated on this basis. The microtopography and pore structure of wood ceramics were also analyzed. The test results show that an increase in the concentration of phenolic resin led to a decrease in the MLR, VSR, and AP of WPWC and WFWC, while their BS exhibited an increase. When the concentration of phenolic resin was 60 %, the phenolic resin yielded a BS of 8.70 MPa and 9.20 MPa for WPWC and WFWC, respectively. Furthermore, the microstructures of both WPFC and WFWC reveal hierarchical porous structures. The difference is that WPFC has a dispersed three-dimensional network topology in its overall morphology, which is mainly formed by filamentous or long linear glass carbon in wood ceramics dominated by carbon. The natural and consistent pore structure of WFWC is comparable to a three-dimensional honeycomb structure, the primary mesoporous size was around 40.28 nm and the main macropore size was more than 10,000 nm. It elucidates the pore structure of WPWC and WFWC, characterized by “hierarchical porosity”, the differences and relationships between porous wood ceramics derived from powdery and fibrous biomass as raw materials were analyzed, which contributes to the advancement of the fundamental principles of wood ceramics and establishes a theoretical basis for the practical exploration and development of biomass materials.