Effects of vibration force field on the interfacial interaction and morphology of polystyrene/poly(methyl methacrylate) blends

Immiscible polystyrene (PS)/poly(methyl methacrylate) (PMMA) blends were extruded using an electromagnetic dynamic plasticating extruder. Effects of vibration force field on the interfacial interaction and morphology of PS/PMMA blends were studied by differential scanning calorimetry (DSC), IR spectra, scanning electron microscope (SEM) and small angle X-ray scattering (SAXS). Results show that the introduction of a vibration force field into the extrusion process increases the solubility of the two components of PS/PMMA blends, which seems to be a physical compatibilization as indicated by the IR spectra. The enhanced interfacial interaction and the increased shear effect caused by vibration improve the dispersion of the dispersed phase. With application of vibration, the PS/PMMA blends exhibit a smaller drop size and a narrower particle size distribution. The morphologies of PS/PMMA blends with different compositions have a different response to vibration forces; the mean domain size of 25/75 PS/PMMA blends has a higher speed of decrease with increase of vibration amplitude or frequency. The Porod invariant data as determined by SAXS indicate that introduction of vibration improves the homogeneity of the PS/PMMA system.