Development and Characterization of Epoxy-Based Polymer Composites Containing Piezoelectric and Electrically Conductive Fillers

Piezoelectric materials are widely used in the field of structural health monitoring due to their ability to convert mechanical energy into electrical energy. This is achieved by generating an electrical potential difference through polarization under mechanical stress, which enables them to produce an electricity or voltage output. The aim of this study is to develop new piezoelectric polymer composites based on epoxy/ polyvinylidene fluoride (PVDF)/BaTiO
3
(BT) or silver additives. The composite was prepared by adding 20 wt.% PVDF and/or 5, 20 wt.% BT microparticles and 5 wt.% silver nanoparticles. The effects of different compositions were investigated in terms of their fracture toughness, tensile properties, piezoelectric response, thermal behaviour, and morphologies. The critical fracture energy of neat epoxy was obtained as G
IC
=810 J/m
²
. The addition of PVDF, BT and silver nanoparticles increased the critical fracture energy of the epoxy, with the maximum fracture energy value obtained as 1405 J/m
²
for the PVDF-BT containing epoxy composite. The addition of PVDF decreased the tensile modulus but increased the tensile strength, while silver nanoparticles decreased the tensile strength value from 59.5 MPa to 49.6 MPa due to agglomeration. The highest overall mechanical, thermal and piezoelectric response was observed in the epoxy-based polymer composite containing 20 wt.% PVDF and 5wt.% BT, which exhibited a maximum voltage output of ~0.2 V.