Fabrication of palmitic acid-grafted epoxidized natural rubber leakage-resistant phase change composites for energy storage

The development of phase change composites (PCCs) with effective leakage-resistant and high latent heat for efficient energy storage remains a significant challenge. Palmitic acid (PA) grafted epoxide natural rubber (ENR) was selected as the matrix (ENR-PA), with PA as the phase change material. PCCs with ENR-PA matrix prepared using different feed ratios of PA-to-ENR were fabricated under PA loading of 50 wt%. The effects of feed ratio on the PCC structure, latent heat, and leakage resistance were systematically investigated. The study revealed that the PCC prepared with a PA-to-ENR feed ratio of 0.5 as the matrix (ENR-PA₁) exhibited the optimal overall performance, characterized by the highest latent heat and the lowest leakage rate. PCCs with different PA loadings were prepared based on ENR-PA₁. When the PA loading was 60% (ENR-PA₁/PA-60%), the latent heat of PCC was 123.6 J/g, and the leakage rate was only 1.3% after 8 h at 75 °C. After 100 cold-hot cycles, the latent heat of ENR-PA₁/PA-60% was 121.6 J/g, with only a 1.6% attenuation. This straightforward and feasible PCC preparation strategy offers a promising choice for fabricating thermal energy storage materials with high phase change enthalpy and low leakage rates, demonstrating promising application prospects.