POLYETHYLENE GLYCOL/WOOD FLOUR PHASE CHANGE MATERIALS INCORPORATED INTO BIODEGRADABLE WOOD PLASTIC COMPOSITES FOR THERMAL ENERGY STORAGE

To enhance the mechanical and thermal stability of wood-plastic composite phase change materials (WPC PCMs), polyethylene glycol (PEG)/wood flour (WF) PCMs were prepared via solution impregnation. These were added to cellulose, polycaprolactone (PCL), and polylactic acid (PLA)-blended degradable plastics and then compression-molded into WPC PCMs. The materials were characterized using mechanical and thermal tests (SEM, FT-IR, DSC, TG). Research shows that capillary action enables WF to encapsulate PEG, reducing post-phase transition leakage and facilitating heat storage. As PEG content changes, phase change enthalpy and temperature first decrease, then increase, and finally stabilize, with a high latent heat of 33.97 J/g. WPC PCMs exhibit good thermal stability with increasing PEG. When the addition amount of PEG was 30%, compared with the initial decomposition temperature and the maximum decomposition temperature of the material without PEG addition, they increased by 24.4°C and 26.9°C respectively.PEG increases the thermal conductivity of WPC PCMs within a certain range, but the increase is limited. Due to its simple preparation, WPC PCMs have broad application prospects in solar and biomass energy storage.