Preparation, characterization and molecular dynamics of novel pre-plasticized nitrocellulose composite microspheres containing burning rate catalysts

• Published in: Journal of energetic materials 2021-04, Vol.39 (2), p.228-245
• Main Authors: Wu, Yanguang, Chai, Kuan, Cai, Lu, Yi, Zhuangcheng
• Format: Article
• Language: English
• Subjects: Blending effects; Burning rate; Catalysts; Cellulose esters; Cellulose nitrate; Composite materials; Distribution functions; Glycidyl azide polymer; Heat transfer; Hydrogen bonding; Microspheres; Molecular dynamics; Nitrocellulose microsphere; plasticizing mechanism; Polymers; Radial distribution; Roundness; Solution blending; theoretical simulation; Thermal decomposition; Van der Waals forces
• ISSN: 0737-0652; 1545-8822
• DOI: 10.1080/07370652.2020.1776418

In this contribution, pristine nitrocellulose (NC) and novel NC/glycidyl azide polymer (GAP) composite microspheres with uniformly dispersed burning rate catalysts, a high degree of roundness and excellent fluidity, were successfully prepared using a solution blending procedure. The burning rate catalysts had an apparent catalytic effect on the thermal decomposition of the novel composite microspheres and promoted their heat release. Furthermore, molecular dynamics simulation was conducted to explore the plasticizing mechanism of GAP. NC/GAP showed improvements in free volume and radius of rotation of 82.14% and a 50.13%, respectively, compared to pristine NC, indicating that GAP molecules had increased mobility in the NC matrix. In addition, the radial distribution function showed that NC/GAP exhibited higher intermolecular intensities from both hydrogen bonding and van der Waals forces compared to those of pristine NC, which was consistent with the value obtained for the average intermolecular interaction energy. The experimental and computational studies showed that there may be good potential for the design and manufacture of novel pre-plasticized NC composite microspheres having low vulnerability and good plasticizing performance for preparation of propellant.