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. Thermal stability was achieved for experiments within the 223 - 393 K temperature range. The design allows simultaneous measurements of temperature, pressure and strain during the barocaloric cycle. The system proved to be fully-functional through three basic experiments using natural rubber. Samples exhibited large temperature variations associated to the {\sigma}b-CE. Stress-strain and strain-temperature curves were also obtained, providing information for the indirect measurement of caloric variables. These preliminary results open interesting perspectives for further {\sigma}b-CE studies.