Enhanced thermal and mechanical properties of hydrophobic graphite-embedded polydimethylsiloxane composite

This work reports the facile fabrication of graphite embedded polydimethylsiloxane (PDMS) composites using in-situ polymerization and investigates the impact of graphite fillers on their mechanical and thermal characteristics. The extensive characterization is performed using scanning electron microscopy (SEM), contact angle measurement system, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The mechanical properties of the prepared composites are investigated by compression test which explores the possibility of manipulating the PDMS properties by unswervingly modifying the concentration of conductive graphite filler which improves filler dispersion in the PDMS and increases its interaction with graphite fillers, thereby enhancing the mechanical and thermal characteristics of the manufactured composites. The current study confirms the hydrophobicity (contact angle similar to 112 degrees) of the fabricated composites and investigates the impact of graphite concentrations ranging from 2.5%-20% on the mechanical properties of pure PDMS polymer during compression testing. Furthermore, the thermal conductivity, thermal diffusivity, and specific heat of graphite-embedded PDMS were around 82%, 505% and 1040% higher than that of the pure PDMS, respectively, while the mechanical properties for the compressive module ranged from 3.2 MPa to 4.9 MPa with the elastic behavior up to 40% strain.