Effect of carbon nanotube and microencapsulated phase change material utilization on the thermal energy storage performance in UV cured (photoinitiated) unsaturated polyester composites

The utilization of phase change materials in the synthesis of polyester is an economically viable approach for the production of polymer composites with remarkable thermal and mechanical characteristics, thereby facilitating thermal energy savings. This study manufactured a series of unsaturated polyester resin (UPR)/carbon nanotubes (CNT)/MPCM composites via mechanical mixing and ultrasonication processes and the produced composites were cured with ultraviolet (UV) curing technology. The unsaturated polyester resin was utilized as a support matrix, and to improve the thermal conductivity of MPCM-UPR composites, CNT were introduced into the matrix. This paper discusses the effect of CNT and MPCM on the mechanical, thermal, and thermal regulative performance of polyester composites. A 10 wt% incorporation of MPCM led to an almost 77 % and 15 % drop at Charpy impact strength and Shore D hardness values of reference UPR, respectively. Similarly, the introduction of substitution of 0.005 wt% of CNT reduced the impact strength of the specimen with 10 % MPCM by 31 %, while it increased the Shore D hardness by almost 5 %. Although the thermal conductivity of reference resin was reduced by 15 % with a 10 % addition of MPCM, CNT content increased the thermal conductivity values by almost 20 % regardless of MPCM concentration. The onset melting and freezing temperatures of MPCM were found to be 21.71 and 22.74 °C, respectively; while for the composites with and without CNT, this value ranged between 20.70 and 22.39 °C and 22.45–22.90 °C, respectively. Thermoregulation test results indicate that MPCM improved the thermal energy storage capacity of composites. The results of this research will be of great significance in order to gain a more comprehensive understanding of the thermal properties of polyesters with MPCM/CNT, thus allowing for the utilization of this material as a latent heat thermal energy storage system for energy conservation.