Directional Crystallization of Polyethylene Oxide - Polyvinyl Acetate Blends

Directional crystallization of polymers is a promising pathway to reuse of end-of-life polymers, specifically of multi-layered plastics. Recent efforts including studies on the directional crystallization (or zone annealing) of semicrystalline polymers report the preferential orientation of polymers in the direction of the imposed temperature gradient. In this work we study the directional crystallization of miscible polyethylene oxide (PEO) and polyvinyl acetate (PVAc) blends. Under isothermal crystallization conditions, especially at temperatures in excess of 313K, the PVAc diffuses into the interfibrillar zone as opposed to interlamellar organization obtained at lower temperatures. Subjecting these blends to directional crystallization at different speeds allows us to access different crystallization rates - this presumably allows us to control the spatial dispersion of the PVAc in the flow-aligned PEO domains, with consequences on properties. We shall explore these two topics through a judicious combination of experiments.