Evaluation of Biomass Softwood Composites: Structural Features and Functional Properties of Advanced Engineered Wood

Softwood-based composites are increasingly used in structural and nonstructural applications owing to their renewability, cost-effectiveness, and favorable strength-to-weight performance. This study applies a systematic literature review and comparative analysis, drawing on approximately 140 sources, to synthesize current knowledge on the physicochemical, mechanical, thermal, and environmental characteristics of engineered wood products derived from softwood species. The intrinsic lignocellulosic composition of softwood, comprising roughly 40%–45% cellulose, 25%–30% hemicelluloses (with mannose as the predominant sugar), and 27%–30% lignin, strongly influences hydrophilicity, stiffness, and thermal behavior. Mechanical properties vary across engineered wood product classes; for example, plywood exhibits a modulus of rupture of 33.72–42.61 MPa and a modulus of elasticity of 6.96–8.55 GPa. Microstructural and spectroscopic analyses highlight the importance of fiber–matrix interactions, chemical bonding, and surface modifications in determining composite performance. Emerging advanced materials, such as scrimber, with densities of 800–1390 kg/m3, and fluorescent transparent wood, achieving optical transmittance above 70%–85%, demonstrate the expanding functional potential of softwood-based composites. Sustainability assessments indicate that coatings, flame-retardants, and adhesives may contribute to volatile organic compound emissions, emphasizing the need for lower-emission, bio-based alternatives. Overall, the findings of this systematic review show that softwood-based composites deliver robust, quantifiable performance advantages and hold strong potential to meet the rising demand for sustainable, low-carbon engineered materials.