Preparation and properties of gypsum-based heat storage and preservation material

The paraffin/expanded perlite shape-stabilized phase change material (PCM) was prepared by absorbing paraffin into pores of expanded perlite with vacuum adsorption method (VA method). The gypsum-based heat storage and preservation material was prepared by mixing the prepared paraffin/expanded perlite shape-stabilized PCM and gypsum. Scanning electron microscopy (SEM) was used to investigate the influence of the VA method and free adsorption method (FA method) on the microstructure of the paraffin/expanded perlite PCM. Differential scanning calorimetry (DSC) and exudation experiment were used to test the thermal property and shape-stability of the paraffin/expanded perlite PCM, respectively. The thermal conductivity, bending strength and compressive strength were also tested. The results showed that paraffin was uniformly distributed in pores of expanded perlite in the paraffin/expanded perlite PCM prepared with the VA method. The paraffin/expanded perlite PCM had satisfied shape-stability. The thermal conductivity of gypsum was decreased by addition of the paraffin/expanded perlite PCM. The adsorption amount of paraffin had little effect on the bending strength and compressive strength of the gypsum-based heat storage and preservation material.

► Paraffin are absorbed into perlite by vacuum method to prepare paraffin/expanded perlite shape-stabilized PCM.
► The prepared paraffin/expanded perlite shape-stabilized PCM prepared by VA has more desirable shape-stability than that prepared by FA method.
► The melting temperature of the paraffin/expanded perlite shape-stabilized PCM is 28.11 °C, and the latent heat of it is 147.92 J/g.
► The adsorption of paraffin makes the thermal conductivity coefficient of the expanded perlite/gypsum decreased and has little influence on the bending and compressive strength of the gypsum-based heat storage and preservation material.