Research on the Factors Influencing the Thermoplastic Rheological Properties of Wood

The rheology of wood thermoplastics is a crucial factor in enhancing wood utilization efficiency, significantly impacting the various applications of wood. The rheological properties of these thermoplastics are influenced by several variables, including moisture content, temperature, and fiber morphology. This study aims to investigate the rheological characteristics of wood under differing moisture levels (from absolute drying to water-impregnated states), thicknesses (ranging from 3 to 15 mm), compression methods, and compression conditions through a series of compression tests. The results show that moisture content and thickness substantially affect the rheological properties of wood thermoplastics, whereas thermal compression conditions exert a comparatively minor influence. Additionally, analysis of the content of the three primary elements in wood, alongside microscopic morphological examination, reveals that increased fiber length and higher length–diameter ratio are associated with enhanced rheological properties of wood thermoplastics. Notably, the influence of cellulose content (ranging from 40%–50%) on these rheological characteristics appears to be limited.