Enhancing elastocaloric effects in SEBS polymers through SiO2-induced conformational changes

With the increasing demand for refrigeration in modern society, the environmental costs associated with traditional vapor compression refrigeration have become increasingly significant. In this context, polymer elastomers based on the elastocaloric effect have emerged as a promising alternative due to their high energy efficiency, ease of processing, and low cost. However, the elastocaloric response of current polymer elastomers still falls short of practical application levels, and effective methods to enhance the elastocaloric effect are lacking. Here, we investigated the elastocaloric effect of poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS) based composites from the perspective of conformational changes through in situ testing. We demonstrated that the introduction of SiO2 increases the conformational entropy of the composites in the relaxed state while reducing it in the stretched state, resulting in greater conformational changes during deformation. With the optimal composition, the adiabatic temperature change of the composites reached −16 K, and the isothermal entropy change reached 163.1 J kg−1 K−1, representing a 30% improvement compared to SEBS. This study provides a novel approach for enhancing the elastocaloric effect of polymer elastomers, potentially advancing the commercialization of polymer-based elastocaloric refrigeration.