Properties evaluation of polyester composites with fillers for electrical sector applications

Developing advanced polymeric composites is pivotal for enhancing the performance and sustainability of materials used across various industries, including the electrical sector. This study investigates isophthalic-polyester composites reinforced with clay feldspar, calcite, and glass fiber powder for their mechanical, electrical, thermal, and morphological properties. Compression tests showed that IsoFG50 (fiberglass power) exhibited the highest mechanical strength, with a 24% increase in compressive stress (140 MPa) and a 60% increase in modulus of elasticity. In contrast, IsoCF50 (clay feldspar) showed the lowest tensile strength, decreasing from 40 MPa (pure polymer) to 15 MPa. Electrical conductivity tests confirmed that all composites exhibited insulating behavior (conductivities in the range of 10− 6 Ω−1 m− 1), ensuring suitability for electrical applications. SEM (scanning electron microscopy) analysis showed that IsoFG50 had a well-distributed glass fiber network, which improved mechanical integrity, while IsoCF50 had weak matrix adhesion with visible gaps. Contact angle measurements showed that IsoCF50 and IsoFG50 had a contact angle of over 90°, confirming hydrophobicity. Flammability tests classified all reinforced composites as non-flammable, underlining their applicability in the electrical sector. These results emphasize the potential of polyester composites with mineral fillers for insulating applications, protective components, and structural elements in electrical systems. The improved mechanical properties, electrical insulation, and resistance to environmental stresses indicate that they represent a sustainable alternative to conventional materials for electrical applications. Future research should focus on optimizing filler dispersion and improving interfacial adhesion to maximize the performance of the composites.