Relaxation properties of polyoxymethylene and ethylenea€“octene copolymer blend in solid and melt states

摘要

Rheological properties of polyoxymethylene (POM) and ethylenea€“octene copolymer (EOC) in solid and melt states were investigated. Blends were prepared with a twin screw extruder at broad component wt-to-wt ratios (10, 30, 50, 70, 90 wt% of EOC). The morphology as well as calorimetric, rheological, and elastic properties of the blends were studied. The investigation showed that POM/EOC blends were heterogeneous in nature and had a broad phase transition region between 30 and 70 wt% of POM. Because during processing droplet breakup is enhanced for EOC-rich systems, respective blends show a€?bettera€? morphology with smaller particle sizes. It was, however, observed that rheological and dynamic characteristics (such as storage E?￠ and loss E?2 modules as well as shear elastic G?￠ and viscous G?2 modules) were highly influenced by intrinsic incompatibility of POM and EOC. Besides, also the crystallization specifics of the investigated blends influenced their E?￠ and E?2.