Phase transitions and mechanical properties of nitrocellulose plasticized by glycidyl azide polymer and nitroglycerine

Abstract

Films of nitrocellulose (NC), glycidyl azide polymer (GAP), and nitroglycerine (NG) have been evaluated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, dynamic mechanical analysis (DMA), and tensile testing. The SEM micrographs demonstrate that, even at low GAP concentration, a portion of GAP will coalesce into spherical domains due to a saturation effect. This is related to the inability of higher molecular weight GAP to effectively situate itself between NC polymer chains. The addition of a small fraction of lower molecular weight NG completely changes this behavior. DMA confirms that two transitions are present and can be attributed to a plasticizer rich phase (β), a polymer rich phase (α) and that NC plasticized with GAP is in accordance with the Gordon‐Taylor equation. Tensile results show that the addition of a small fraction of NG to a NC/GAP based‐formulation increases elongation at break to values similar to that of the NC/NG base formulation. The combination of these two plasticizers, GAP and NG, allows for the plasticization of NC at significantly lower environmental and human toxicity levels.

Preparation and characterization of polyacrylonitrile/nitrocellulose engineering blend

“…The morphology of partially miscible polymer blends at lower loading of NC (10 wt%) shows very small size spherulites shown in Figure 8a. NC could not affect phase size of polymer system up to certain loading 45 . As increased NC loading (20%–30%), formation of more spherulites was observed shown in Figure 8b, c.…”

Linear Burning Rate and Erosivity Properties of Nitrocellulose Propellant Formulations Plasticized by Glycidyl Azide Polymer and Nitroglycerine

“…Recent work from this laboratory, has evaluated the plasticization properties of GAP and demonstrates that, by itself, it does not efficiently plasticize NC due to its high molecular weight. However, that same work also shows that an NG/GAP mixture is an efficient way to plasticize NC and leads to similar mechanical properties when compared to the NC‐NG formulation [30].…”

“…It is also important to note that from our previous work on the thermomechanical properties of similar formulations, there seems to be a correlation between the presence of the β relaxation and a sharp increase in the LBR at high temperature [30]. In order to better observe this phenomenon, the ratio of LBR at 63°C and À 46°C for both NG and GAP concentration ranging from 0 to 40 wt%.…”

Graft Semi-Interpenetrating Polymer Network Phase Change Materials for Thermal Energy Storage

“…Solid–solid PCMs are materials where the crystalline structure changes to another crystalline structure or amorphous phase. Solid–solid PCMs consist of inorganic, organic, and polymer-based PCMs. − …”