Nano to microblend formation in poly(ethylene-co-methyl acrylate)/ poly(vinylidene fluoride) blend and investigation of its anomalies in rheological properties

Polymer blending is a classical approach to develop new generation materials. The investigation of material rheological and microstructure properties of the blend is essential for product development with optimized properties. In this study, poly(ethylene-co-methyl acrylate)/poly(vinylidene fluoride) (EMA/PVDF) blend prepared by melt-mixing in which PVDF concentration is varied from 10 to 40 wt%. The morphology studies of the blends using electron microscopy revealed the formation of matrix-droplet architecture. PVDF nano-droplets were dispersed in the EMA matrix, and droplet coalescence observed with the increase in PVDF concentration. The storage modulus was increased after 150 s in the time resolved modulus studies indicates the presence of specific interactions and possible physical crosslinking during the processing. Fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC) analysis delineate the specific interactions formed during the processing. The shift in the characteristic stretching peak of the carbonyl group from 1732 to 1738 cm⁻¹ and the formation of an exothermic peak at 100 °C during the heating cycle of the calorimetric study demonstrated the presence of the anomalies during processing. Optical microscopy and small-angle X-ray spectroscopy (SAXS) were employed to study the time resolve crystallization of EMA under isothermal condition. The increase of crystals formation with time was observed from the optical microscopy.