Effect of nitrocellulose (NC) on morphology, rheological and mechanical properties of glycidyl azide polymer based energetic thermoplastic elastomer/NC blends

As a new kind of propellant binder, energetic thermoplastic elastomer (ETPE) can improve propellant recyclability and environmentally friendly disposal. The rheological behavior of the ETPE binder can be beneficial to identify suitable and safe conditions for processing ETPE propellants. In this paper, ETPE/nitrocellulose (NC) blends with different mass ratios of NC to ETPE were prepared by the physical mixing method. The heat of explosion and the morphological, thermal, mechanical and rheological properties of the resulting blends were studied systematically. It was found that the heat of explosion of ETPE/NC blends increased with increasing NC content. SEM images showed that the NC domains in the blends changed from tiny pieces to fibers with increasing NC mass ratio, which indicates phase separation in the blends. The tensile mechanical properties of the blends had a peak value when the NC content was 10 wt%, and then increased with the increasing addition of NC. The thermal behavior made clear that the ETPE and NC were partially miscible. Rheological studies on dynamic strain sweep and frequency sweep demonstrated that the content of NC in the blends had a monotonic effect on their rheological properties at 130 °C. Rheological studies also showed that the rheology of the blends is dependent on temperature. The Cole − Cole and Han plots confirmed phase separation in the blends.