Weight Fraction Of PMMA Research Articles

Miscibility of PVDF/PMMA blends examined by crystallization dynamics

The crystallization dynamics of blends of poly(vinylidene fluoride) (PVDF) with atactic-, syndiotactic- and isotactic-poly(methyl methacarylate)s (PMMA) were analysed by differential scanning calorimetry under isothermal conditions. Crystal growth rate ( G) decreased with increasing weight fraction of PMMA (φPMMA) for PVDF/at-PMMA and PVDF/syn-PMMA blends. However, G of PVDF/iso-PMMA blends depended only on the degree of supercooling (Δ T) and was independent of φ spPMMA. Surface free energy (σ) of PVDF crystals evaluated from G and nucleation rate depended on φ spPMMAfor PVDF/at-PMMA and PVDF/syn-PMMA blends, although σ of PVDF/iso-PMMA was almost constant and independent of φ spPMMA. These results suggest that PVDF/at-PMMA and PVDF/syn-PMMA blends are miscible but PVDF/iso-PMMA blends are immiscible, a finding which was confirmed by the phase diagrams as determined from cloud point measurements.