Using nanoclay in unsaturated polyester insulator for inhibition the migration of nitroglycerin in double base solid propellants

Nitroglycerin (NG) is used as an energetic plasticizer in double-base propellants. The use of NG turned out to cause stability and performance problems for the double base solid propellant (DB) because NG could migrate from the propellant during storage, and soften it at high inclusion levels [۱]. The loss of adhesion between the propelant and insulator is one of the most important problems in (DB) motors due to this migration. So in this study, unsaturated polyester polymer UP-۱ was synthesized from propylene glycol and phthalic anhydride and modified with various percentages of nanoclay filler, and investigated for inhibition of migration of NG in DB [۲]. The prepared modified polyesters were proved using Fourier FT-IR spectroscopy. Various parameters including of the migration and penetration rates of NG in modified insulators were evaluated. Migration and penetration rates tests involve of immersion test. This test was conducted to estimate NG penetration coefficient in the insulator and mass of penetrated NG. The penetration coefficient of penetrated NG into in modified polymer insulator with nanoclay filler shows that the polyester insulator containing ۱۵% of nanoclay filler has the lowest penetration coefficient ۲.۹۵×۱۰-۵ cm۲/s, in comparison with the control unsaturated polyester, with penetration coefficient ۱.۰۲۷×۱۰-۴ cm۲/s, the final analysis of migration shows that the ۱۵% nanoclay filler with a migrated mass of around ۲.۵۷ is the most appropriate filler. Changes in nitroglycerin absorption percentage based on mass between ۱۴ hours-۱۵ days are in the range of ۰.۰۰۲۸-۰.۰۵۱۵, while for control unsaturated polyester in this time rang, the absorption percentage is equal to ۲.۰۱۰-۱۸.۶۶۳. This results shows that the unsaturated polyester insulator modified with nanoclay filler has good efficiency for inhibition NG migration in double base solid propellants.

کلیدواژه ها:

Propellant ، Nitroglycerin Migration ، Polyester Insulotor ، Nanonclay