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The kinetics of reaction between HTPB (Hydroxyl Terminated Polybutadiene) and TDI (Toluene
Diisocyanate) bas been investigated. Back
procedure is used for determination of
extent of reaction. In this procedure the additives will not disturb the experiments. The reaction was only investigated up to
gel point, because of unreproducibility for
postgel samples. The extent of reaction
was measured at four different
temperatures for polymeric binder and the constants of apparent second order rate
equation were obtained. Because of
different situation of isocyanate groups in TDI a break appears in the said quadratic curves. Also cure ratio parameter (R or equivalent ratio of NCD to OH) was varied, but the effect of variation of this ratio on the rate of reaction was not very much sensible (R was varied from 0.84 to 0.95). Finally the effect of Ammonium perchlorate was studied. It is found that as the extent of this additive is increased, its reducing effect of reaction rate wi)) increase, and as Ammonium perchlorate sizing becomes larger the rate of reaction will decrease.