Structure Formation and Interaction of Polyethylene and Polycaprolactone in Blends

The mutual effects and the structure of interface in blends of low-density polyethylene (PE) and polycaprolactone (PCL) with different ratios of components (differing by 10 wt %) were studied. The creation of blended composites of this kind based on one polymer capable of photodegradation under the action of ultraviolet radiation and another polymer prone to hydrolytic degradation under the action of microbiota makes it possible to obtain materials with an enhanced ability to undergo fast abiotic and biotic degradation after use. Blended films with high PCL contents (over 80 wt %) showed mutual compatibility of polymers, forming a developed interfacial layer, which imparts increased tensile strength and hardness to the film. The phase inversion ranges were determined to be 10–30 wt % PCL (continuous PE phase with a discontinuous PCL phase), 40–60 wt % PCL (net-in-net structure) and 70–90 wt % (continuous PCL phase with a discontinuous PE phase). The composite containing 70 wt % PCL was characterized by the greatest defectiveness of internal structure, and the composite with 90 wt % PCL had the most optimum set of both mechanical and technological properties.