Experimental setup for measuring the barocaloric effect in polymers: Application to natural rubber

Barocaloric materials have shown to be promising alternatives to the conventional vapor-compression refrigeration technologies. Nevertheless, barocaloric effect ({\sigma}b-CE) has not been extensively examined for many classes of materials up to now. Aiming at fulfilling this gap, this paper describes the development of a high-pressure experimental setup for measuring the {\sigma}b-CE in polymers. The design allows simultaneous measurements of temperature, pressure and strain during the barocaloric cycle. The system proved to be fully-functional through basic experiments using natural rubber. Samples exhibited large temperature variations associated to the {\sigma}b-CE. Strain-temperature curves were also obtained, which could allow indirect measurements of the isothermal entropy change.