Structure and properties of biomorphic carbon scaffolds based on pressed birch and alder wood

The effect of prepressing of birch and alder wood on the pyrolysis process, structure and properties of biocarbon scaffolds were investigated. It is shown that after pressing process, internal stresses in the wood are preserved, which leads to a change in shrinkage during pyrolysis, especially in the pressing direction. The limitation of the samples expansion in the pressing direction made it possible to increase the density of biocarbon scaffolds (up to ∼ 1 g/cm³) and to obtain a linear dependence of their density on the density of compressed wood. Deformation of wood did not lead to a noticeable change in the atomic structure of biocarbon, but defects in the cell walls that affect the electrical resistivity of the biocarbon scaffolds were formed. The bending strength of biocarbon samples based on compressed wood was primarily determined by their density and weakly depended on the particular species. The obtained strength values were not inferior to the published data, which indicates that the defects formed during deformation were not stress concentrators.