Nanostructure Evolution Mechanisms During Slow Load‐Cycling of Oriented HDPE/PA Microfibrillar Blends as a Function of Composition

Abstract

Abstract Oriented precursors of MFCs consisting of HDPE and PA6 or PA12 are studied during strain‐controlled slow load‐cycling. In the PA6‐containing blends a strongly retarded nanostrain response is detected. Compatibilization induces nanostrain heterogenization. Stress fatigue is lower in the PA12 blends, but hardly decreased by the compatibilizer. Selective migration of the compatibilizer into a disordered semi‐crystalline fraction of the HDPE matrix can explain the findings. The semi‐crystalline HDPE entities in PA6 blends appear more disordered than in PA12‐blends. An analysis of the HDPE nanostructure evolution during cycling reveals epitaxial strain crystallization. Uncompatibilized PA6 blends cycled about high pre‐strain show plastic flow but nanoscopic shrinkage in the semi‐crystalline stacks. magnified image