Microhardness investigation on thin films of virgin and electrically aged pure PVF and isomorphic polyblends of PVF/PVDF

Abstract

Replacement of conventional materials by polymeric materials (blends/composites) with improved mechanical performance is of immense importance for modern technology. Blending of fluoro polymers can contribute to such synergistic properties. PVDF, as a semi-crystalline fluoro polymer, has been blended with PVF fluoro polymer to form isomorphic polyblend specimens by altering the wt% of PVDF using a solution casting technique. Microhardness investigations have been undertaken using the Vicker's indentation technique; measurements of Vicker's hardness number (Hv) were carried out on virgin (untreated) and electrically stressed pure PVF and PVF/PVDF isomorphic polyblend specimens by a fixed step voltage at a fixed high temperature. The results of variation of Hv as a function of applied load are explained in terms of strain hardening phenomenon in virgin samples along with their mechanical properties. The increase of hardness produced as a result of variation of PVDF wt% within the PVF matrix has been interpreted in terms of a change in chain crosslinking. The observed higher value of hardness number in the case of electrically stressed specimens is suggested to result from modification in inter- and intramolecular interactions in such samples. © BME-PT and GTE.