Hygrothermal performance of temperature-humidity controlling materials with different compositions

Abstract In this paper, gypsum, zeolite, expanded vermiculite, and shell powder were used as substrates respectively, and phase change microcapsules were mixed into different substrates at a certain mass ratio to prepare phase change microcapsule composites with different substrates. Through the moisture absorption and desorption performance experiments, water vapor permeability coefficient experiments, and isothermal equilibrium moisture content experiments, the moisture buffering properties of composite phase change materials with different substrates were compared. Differential scanning method, specific surface area and pore analysis, and scanning electron microscope were used to study their thermal performance, apparent morphology, and pore distribution characteristics. The moisture buffering performance index of zeolite-based phase change microcapsule composites is 1.5 times that of pure zeolite materials and 2 to 10 times that of other materials. The zeolite-based composites with good stability, large phase latent heat, and the best humidity controlling performance in all substrates have the phase transition temperature range (20 ~ 25℃) closed to the ideal room temperature, which are the most suitable for use as temperature-humidity controlling building materials.