Co-crystallization behaviors and thermo-physical properties of SSPCM consisting of an extra low melt viscosity HDPE and paraffin waxes

Shape stabilized phase change materials (SSPCMs) consisting of an extra low melt viscosity high-density polyethylene (lv-HDPE) and paraffin waxes (PW) were fabricated using a twin screw extruder. Thermal and mechanical properties of these composites were assessed. The latent heats (?H) of the SSPCMs fabricated were up to 78 J g(-1). Co-crystallization between lv-HDPE and paraffin waxes increased with increasing wax content. Dynamic mechani-cal thermal analysis confirmed the paraffin wax having a higher melting point (H-PW, Tm ranging from 56 to 58 degrees C) plasticized the lv-HDPE, decreasing both its crystalline content and melting temperature. Static mechanical testing, dis-regarding the form of deformation (tension, flexural, and compression), showed addition of paraffin waxes resulted in a diminution of all mechanical properties of lv-HDPE, but the properties of the composites with H-PW were good in comparison to those with a lower melting point wax (L-PW, Tm rang-ing from 18 to 23 degrees C). Evidences from Cole-Cole plots obtained from oscillatory rheology experiments showed there was no interaction between lv-HDPE and H-PW, inducing a heterogeneous blend in contrast to the more homogeneous lv-HDPE/L-PW composites.