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

Abstract

As a new kind of propellants binder, energetic thermoplastic elastomer (ETPE) can make propellant recyclability and environment friendly disposal. The rheological behavior of ETPE binder could be beneficial to identify suitable and safe conditions for processing ETPE propellants. In this paper, ETPE/NC blends with different mass ratios of NC to ETPE were prepared by physical mixing method. The heat of explosion, morphological, thermal, mechanical and rheological properties of the resulted blends were systematically studied. It was found that the heat of explosion of ETPE/NC blends increased with the increasing of NC content. The scanning electron microscopic (SEM) images showed that the NC domains in the blends changed from tiny pieces to fibers with the NC mass ratio increasing, 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 of the blends had a monotonically effect on the rheological properties of the blends at 130 °C. Rheological studies also showed that the rheology of blends is dependent on temperature. The Cole-Cole and Han plots also confirmed phase separation in the blends.