Solid-State NMR Investigations of Semi-Crystalline PVIBE/ε-PL and PK/PA Blends: Crystallite Size, Type, and Morphology Related to Physical Properties

Crystallinity and the size of crystalline phase of poly(ε-L-lysine) (ε-PL) were determined by solid-state 13C NMR . The decrease in the melting temperature with increasing ε-PL content ascribed to the crystalline phase of ε-PL in poly(vinyl isobutyl ether) (PVIBE)/ε-PL blends was interpreted by the decrease in total lamellar thickness in the crystalline phase of ε-PL. Furthermore, the independence of the melting temperature with ε-PL content for PVIBE/ε-PL/saponite-clay nanocomposites was also explained in a similar way. For polyketone/nylon 6 (PK/PA) blends, the high impact resistance under the wet condition was explained by the characteristic morphology of PK crystalline phase, the increased elasticity due to water absorption in the amorphous phase of PA, and conversion of γ crystallite to the α crystallite morphology of PA (as shown by solid-state 15N NMR).