Effect of Thermal Conductors on Thermomechanical Properties of Stearic Acid–Gypsum Composites

Stearic acid (SA)–gypsum composites containing different thermal conductors (TCs) were fabricated, and their mechanical, thermal, and microscopic properties were studied. The SA–gypsum composites containing 20 wt.% SA exhibited optimal mechanical properties. After 7 days, their flexural and compressive strengths were 3.08 and 8.26 MPa, respectively. The optimal iron particle, copper particle, and expanded graphite particle contents in the TC–SA–gypsum composites were 6 wt.%, 10 wt.%, and 6 wt.%, respectively. However, the mechanical properties of these composites were slightly less than those of the SA–gypsum composite. The thermal conductivities of the iron particle–SA–gypsum, copper particle–SA–gypsum, and expanded graphite particle–SA–gypsum composites were 1.3383 W/(m K), 1.9619 W/(m K), and 2.3651 W/(m K), respectively, which were considerably greater than those of the SA–gypsum composites. In the expanded graphite–SA–gypsum composite, a thermal absorption peak was observed when the temperature rose from 45 °C to 110 °C. The temperature and enthalpy of phase transition were 52.09 °C and 91.36 J/g, respectively.