مروری بر فرمولاسیون بازدارنده‌‌های احتراق بر پایه پلی‌یورتان در پیشرانه‌های جامد دو پایه(علمی-ترویجی)

Insulation of solid propellant to controlling and limiting the burning surface and also to avoid of heat transfer to the solid rocket body is done. This type of coating is defined as inhibitors of combustion. Unsaturated polyesters such as polyurethane are used for good chemical compatibility between double base propellant and inhibitor. In this article, the effect of aromatic groups and the effect of fillers on the amount of produced smoke are examined and results showed a reduction in the amount of smoke with filler increasing and aromatic groups reducing. Also study of the diisocyanate effect shows that symmetrical diisocyanate used in the preparation of polyurethane leads to high modulus, high tensile-tear strength and ultimately reduce the rate of nitroglycerin migration. The effects of chain length polyester on gel time, exotherm peak temperature, mechanical properties and nitroglycerin migration have been investigated. The results showed a significant improvement of nitroglycerin migration, gel time, exotherm peak temperature and mechanical properties when polyester chain length is reduced. The mechanical properties of polyurethane prepared from mixture of polyether polyol and polyester polyol showed improved mechanical properties as a result of synergistic effect between the polyether and polyester.