Effect of temperature on the tensile mechanical properties and creep performance of wood-plastic composites

Uniaxial tensile tests of recycled waste wood plastic composites were conducted at 20, 40, and 60 °C. High density polyethylene (HDPE, 30%) was reinforced with poplar wood (50%), and calcium carbonate (15%), with 5% additives. The load values for three stress levels of 15%, 30%, and 45% were determined at each temperature. Subsequently, 24-h short-term creep tests of WPC were conducted under nine operating conditions. Both the ultimate strength and elastic modulus of the material was found to decrease with increasing temperature. The modulus and ultimate strength decreased from 3890 and 15.0 MPa at 20 °C to 1970 and 7.1 MPa at 60 ℃, respectively. Furthermore, the stress-strain curves of WPC specimens exhibit plastic behavior when the temperature exceeded 40 °C. The creep deformation of WPC was positively correlated with temperature and stress level. The Findley model exhibited distortion in fitting the creep performance of WPC only under the condition of 60 °C and 15% stress level. Conversely, the fractional-order model demonstrated a better fitting effect on the steady-state creep characteristics of WPC under this working condition.