Robust Microencapsulated Silicone Oil with a Hybrid Shell for Reducing Propellant Erosion

Abstract

A morphologically stable silicon oil microcapsule base polystyrene as shell modified with TiO2 and Si3N4 nanoparticles was synthesized, characterized and applied as an inhibitor for high energy propellant to reduce erosion of gun barrel. The composite microcapsules were obtained by an eco‐friendly method. Embedding heat‐resistant TiO2 and Si3N4 nanoparticles in polystyrene shell enhances the reliability of polymeric shell. The anti‐erosion effect of composite microcapsules for high energy propellant was investigated by using an erosion tester. Results showed that the erosion property of high energy propellant with composite microcapsule was significantly decreased when compared to control sample (without microcapsules). It showed a decrease of 20.6 % in erosion mass when 7 wt.% of composite microcapsules were added to the high energy propellant. Moreover, the anti‐erosion efficiency of composite additives exhibited an increasing trend with the increase of their contents. The pressure and time history confirmed that the composite microcapsules also have ability to adjust the combustion performance of high energy propellants. The developed silicon oil microcapsule shows a potential application for propellant erosion additive.

Preparation and Characterization of Metatitanic Acid/Urea‐Formaldehyde Microcapsules as Wear‐Reducing Additives

“…So, the wear‐reducing efficiency of the microcapsule was 16.92 %, 18.54 %, and 18.85 % respectively. In reference [19], silicon oil microcapsules were employed as the wear‐reducing additives, and the wear‐reducing efficiency was 8.3 % and 16.4 % at 1 % and 3 % dosage. It follows that H 2 TiO 3 microcapsules designed and prepared in the paper have at least the same or better wear‐reducing efficiency compared with silicon oil under the erosion tube test conditions.…”

“…In recent years, microencapsulation technology is particularly employed to develop new kinds of additives containing nanoparticles [18]. A typical example is the microencapsulation of silicone oil, a kind of organosilicon with excellent wear‐reducing ability [19]. However, the leakage of silicone oil is unavoidable during the long shelf life of propellants, possibly giving rise to problems which will impair the interior ballistic performance.…”

Influence of Various Flame Temperatures of the Gun Propellant on the Effectiveness of the Erosion Inhibitor and Relevant Mechanisms

“…These high energy propellants exhibit an enhanced flame temperature and severe erosion. The synthetic methodologies of inhibitors have been extensively studied in prior reports − which have also demonstrated their remarkable effectiveness in reducing erosion for a specific propellant formulation. However, the influence of flame temperatures on the inhibitor efficiency has rarely been extensively discussed in relation to various propellant composites.…”

Study on the Flexible Erosion Reducing Additive Containing Silicon and Boron

“…In China, based on microencapsulation technology, researchers develop different types of microencapsulated erosion reducing additives. These materials include TiO2 precursor microcapsules [4], metatitanic acid/urea-formaldehyde resin composite particles [5], silicone oil/urea-formaldehyde resin microcapsules [6], urea-formaldehyde resin/TiO2 composite microspheres [7], hollow TiO2/polyimide nanocomposite particles [8], Si3N4/polymethyl methacrylate/PW composite phase change materials [9], TiO2/BN/polymethyl methacrylate/PW composite phase change materials [10], Si3N4/TiO2/polystyrene composite microcapsules [11,12], and zeolitic imidazolate framework/PW composite phase change materials [13]. Polydimethylsiloxane (PDMS) is effective in reducing erosion and wear, but it is easy to leak.…”