EXCLUSION OF NONCRYSTALLINE POLYMER FROM THE INTERLAMELLAR REGION IN POLY(VINYLIDENE FLUORIDE) POLY(METHYL METHACRYLATE) BLENDS

We investigated the intraspherulitic structure of poly(vinylidene fluoride) (PVDF)/poly(methyl methacrylate) (PMMA) blends using polarized microscopy and small-angle X-ray scattering (SAXS). The structure of the spherulite is coarser with increasing crystallization temperature. The internal crystallinity obtained by SAXS is much larger than its overall value derived from DSC for the coarse spherulite, indicating that the amorphous region between lamellar bundles is large in this structure. For coarser structures, the electron density difference between the crystalline and the amorphous phase, obtained from an analysis of SAXS scattering profiles, is lower. That is, the concentration of PMMA in the interlamellar amorphous region is low in the coarse spherulite. This suggests that PMMA is partially excluded from the interlamellar region in the coarse spherulite.