An innovative strategy to prepare compressed wood with improved dimensional stability and mechanical properties

Abstract

The mechanical properties of wood are significantly enhanced and its application scope is broadened through compression treatment. However, balancing deformation fixation with the performance of compressed wood is challenging. This study significantly enhanced the dimensional stability of compressed wood while preserving its mechanical properties by grafting N-Methylolacrylamide (NMA) onto wood cell walls and applying thermally assisted surface compression. The NMA-modified compressed wood exhibited improved hydrophobic qualities and a considerably low set recovery of only 0.29%, which is attributable to the cross-linked network formed by the condensation of NMA with wood components. Furthermore, the NMA-modified compressed wood exhibited outstanding mechanical properties, such as improved hardness, bending strength, and impact toughness. Its bending strength (263.5 MPa) was approximately 2.6 times greater than that of natural wood (100.3 MPa). NMA-modified compressed wood, which is characterized by high-dimensional stability and mechanical properties, exhibits significant potential as an engineering material.