Development of technical properties of wood plastic composites with woven carbon and glass fiber fabrics

The aim of this study was to improve technological properties of wood plastic composites (WPC) reinforced with woven glass and carbon fiber fabric. For this purpose, 2 different woven fabric (glass and carbon) and 2 different fabric density (~200 gr/m2 ve ~400 gr/m2) were used. 3 different wood flour content (40 %, 50 % and 60 %) and 2 different thermoplastic type (polyethylene and polypropylene) were selected for study. The effect of coupling agent was also investigated. The physical (density, water absorption, surface roughness), mechanical (flexural strength and modulus, tensile strength, hardness, screw withdrawal strength), artificial weathering, thermal (LOI and TGA analysis), and biological properties of samples were investigated. The microscopic examination was also carried out. According to results, significant increase for mechanical properties with reinforcement was observer. Flexural strength was improved up to 262 %, the increase for modulus of elasticity was 246 %. Tensile strength was increased up to 1325 %. Screw withdrawal resistance was enhanced up to 83 %. The highest mechanical properties were obtained from samples reinforced with 200 gr/m2 carbon and 400 gr/m2 glass fiber woven fabric. The high-density polyethylene provided better properties. Since the degradation temperature for glass and carbon fiber is very high, reinforcement also improved the thermal properties of composites according to TGA analysis. It was also observed that reinforcement positively affected hardness of WPCs. After weathering test, the higher flexural strength and modulus of elasticity was obtained from reinforced wood plastic composites with compared to control samples. The changes on the surface of samples exposed to weathering conditions was investigated with ATR-FTIR spectroscopy and microscopic analysis. ATR-FTIR spectroscopy revealed the oxidation reactions in the wood and polymer chemical structure. Light microscopy also showed the photo-degradation on the surface. Increasing wood flour content increased sensitivity against fungus. Scanning electron microscopy demonstrated the position of woven fabric in the wood/polymer matrix. It was seen that woven carbon fiber fabric with 200 gr/m2 better integrated with matrix.