Phase transitions in poly(vinylidene fluoride)-based composite under mechanical stresses

In this work the phase transition in composites based on polyvinylidene fluoride and cobalt ferrite nanoparticles under uniaxial stretching at 100, 200 and 300% is investigated. It was found that when the composite is stretched at 300%, there is a maximum increase in the β-phase fraction from 1% for the unstretched sample to 91%, while the electroactive phase increases from 74 to 92%. It was also found that tensile stretching of the composites leads to an increase in tensile strength: from 5.7 to 85.0 MPa. This tensile pattern also contributes to an increase in coercivity, which is due to the increase in the interparticle distance in the composite structure. These results emphasise the importance of mechanical properties and phase changes in polymer composites containing ferrites for their future applications.