Publication

Abstract : We propose and demonstrate a first Twin -interferometry based optical approach for studying and exploring anisotropy and directional dependent crystallization kinetic of curing polymers under isothermal condition. A commercial polymeric solution of polyvinylidene fluoride hexa-fluoropropylene (PVDF-HFP) with five different concentrations were prepared and utilised for this study. A Twin-interferometer (TIM) is designed to record the rate of shift in Michelson’s fringes caused by rate of change of optical path length of a transparent polymeric solution in two orthogonal directions during curing. Pair of interferogram referred as Twin- interferogram (TIG) is recorded for the sample of all concentration during its liquid to solid transition. An extraction approach for various crystallization parameters such as anisotropy, crystallization half-life time, constants governing the rate and dimensionality of crystallization, and their variation along distinct direction from TIM is demonstrated. The results provided by TIM are verified by a method of anisotropy annihilation and other experimental techniques includes Scanning electron microscopic (SEM), Polarising optical microscopic (POM) and Dielectric spectroscopic studies.