Synergistic Effects of Reduced Graphene Oxide/Calcium Carbonate Nanocomposite on Mechanical and Thermal Properties of <scp>PDMS</scp> Elastomers at High Filler Loadings and Elevated Temperatures

ABSTRACT Elastic silicone‐based polymers such as polydimethylsiloxane (PDMS) are very promising in terms of flexible and thermal management, but their low thermal conductivity and average mechanical performance limit larger applications. In the present article, reduced graphene oxide/calcium carbonate (rGO/CaCO 3 ) nanocomposite was synthesized through portable ball milling and embedded in a PDMS matrix to form an elastomer. The elastomer was developed and cured by adding the curing agent in a 10:2 ratio under controlled environment at 50°C. FESEM and XRD methods were used to verify the homogeneous dispersion of the hybrid nanofiller and enhanced structural organization of PDMS. Thermogravimetric analysis showed a significant increase in thermal stability, and the beginning of degradation was shifted to higher temperatures as a result of limited polymer movement and increased filler‐matrix reactions. Upon incorporation of rGO/CaCO 3 nanocomposite, the thermal conductivity increases monotonically with filler content, reaching about 0.52 W/mK for E40, approximately 205.88% enhancement compared to the neat PDMS. The E40 (0.873 MPa) elastomer shows an increment in UTS of approximately 88.55%, compared to the neat PDMS (0.463 MPa). These synergistic enhancements prove that rGO/CaCO 3 /PDMS (E0, E5, E10, E20, E30, and E40) elastomers can be used in high‐temperature flexible thermal management and energy storage applications.