Compatibility Study of Polyamide 6/Polyvinylpyprrolidone Blend by Viscometry, Melting Point Depression and Morphological Analysis

Compatibility of the blends of polyamide 6 (PA6) and polyvinylpyrrolidone (PVP) was investigated by solution viscosity measurement, melting point depression and morphological analysis. The viscosity data were discussed by using ΔB and Δb criteria [Formula: see text], where b11 b22 and b12 characterize the interactions between polymer molecules (1-1, 2-2 and 1-2), respectively. ΔB and □b ≥ 0, miscible; ΔB and Δb < 0, immiscible). From melting point data of the PA6 component, the polymer-polymer interaction parameter χ12 = −0.069 was derived through the simplified Nishi-Wang equation. The results revealed that PA6 formed a partially compatible blend with PVP. This conclusion was further evidenced by morphological analysis.