Thermal and mechanical properties of treated and untreated Red Balau (Shorea dipterocarpaceae)/LDPE composites

Abstract

Red Balau saw dust was heat-treated at 180 C and 200 C for 1 h. Treated and untreated wood flour were compounded with LDPE at 9%, 20%, and 37% by weight and molded in an injection molding machine. Thermal and mechanical properties of the resultant composites were investigated as a function of filler loadings and treatment temperature. Thermogravimetric analysis revealed an increase in degradation peak temperature (T p ) of the heat-treated wood and composites. DSC revealed a decreasing trend in the degree of crystallinity (X c ) of the matrix when heat-treated wood was used as filler. On the other hand, untreated wood showed an increase in X c with increasing wood content. Tensile modulus increased with heat treatment and filler loading. Furthermore, flexural strength and modulus were found to increase with filler loading.

Mechanism of fiber/matrix bond and properties of wood polymer composites produced from alkaline-treatedDaniella oliveriwood flour

“…The second peak, within the range of 205-380 C, could be ascribed to the degradation of hemicellulose, cellulose, and lignin in all the WPC samples as a result of the oxidation of char residue generated in the first mass loss peak [36]. According to Bryne and Nagle [37], Yang et al [38] and Lafia-Araga and co-investigators [39], lignocellulosic materials which are chemically active, decompose thermo-chemically in the range of 150-500 C, whereas hemicellulose degrades between 150 C and 350 C, cellulose between 240 C and 350 C, and lignin between 250 C and 500 C. The TGA analysis of vHDPE reveals a single-mass loss step with peak degradation temperature at 455 C suggesting the thermal and oxidative decomposition of saturated and unsaturated carbon atoms in PE.…”

Development of novel green and biocomposite materials: Tensile and flexural properties and damage analysis using acoustic emission

“…In a recent work, Mijiyawa et al [8,9] studied the thermal degradation of LLDPE/birch but did not analyze the resulting mechanical damage. More recently, Lafia-Araga et al [10] has tested red balau fibers using various thermal treatments at the fiber level and has observed an increase in the matrix/fiber adhesion that improved the mechanical properties of the material. It is now acknowledged that the use of a coupling agent (CA) is essential to improve the overall quality of biocomposites with such constituents [11][12][13].…”

Effects ofDaniella oliveriWood Flour Characteristics on the Processing and Functional Properties of Wood Polymer Composites

“…The finding on the crystallisation could also be accounted for by the increasing values of H c and reducing values of H m when wood flour with characteristics other than +210-300 μm and 35 wt% were incorporated into vHDPE, thereby resulting in higher energy being released during crystallisation [20].…”

“…The vHDPE is seen to degrade faster at a temperature range between 350 °C and 480 °C, with a lower initial mass loss while the degradation profiles of the WPCs vary between a wider range of 240 °C and 500 °C. Table 1 shows that the peak temperature (T p ) values of the WPCs increased over that of the vHDPE, thereby, indicating that reinforcing vHDPE with wood flour of varying particle sizes/distribution and contents increased the thermal resistance of the neat matrix [9,20]. Table 1 also reveals that the temperature at which 50% mass of the WPCs degrade (T 50% ) as well as the peak degradation temperature (T p ) increased as wood flour particle sizes/distribution increased up to +210-300 μm particle size/distribution, and then decreased sharply when WPCs were reinforced with larger sized wood flour (+300-425 μm).…”

“…In addition, the degree of crystalline of vHDPE (58.77%) was lower than the optimum crystallinity of the WPCs crystallite growth, thereby reducing the mechanical properties of WPCs [4]. When wood flour larger than +210-300 μm and 35 wt% were incorporated into vHDPE matrix, the nucleation mechanism was impeded by close proximity or overlapping of neighbouring wood flour particles as a result of increased packing density [4,20]. In WPCs formulated by reinforcing vHDPE with wood flour smaller than +210-300 μm, it is possible that the spaces between the particles are significantly larger than the amount of spherulites developed within the polymer matrix, hence, the reported reduced crystallisation in this instance.…”