Influences of NCO/OH and triol/diol Ratios on the Mechanical Properties of Nitro-HTPB Based Polyurethane Elastomers

The present study describes the effect of NCO/OH and triol/diol ratios on the mechanical properties of Nitro functionalized Hydroxyl-terminated polybutadiene (Nitro-HTPB) elastomers. The progress of the cure reaction of Nitro-HTPB and toluene diisocyanate (TDI) is evaluated by following up the variations in the IR absorption bands of the NCO stretching and the CO Stretching. Experiments are carried out at NCO/OH ratios (R values) ranging from 0.8 to 1.2 and triol/diol ratios in the range of 0.05-0.7. Also as the R-value increases, the tensile strength increases, and elongation decreases. The rubbery character of elastomers is improved followed by increased rigidity with an increase in triol/diol value of 0.05. In general, desirable mechanical properties were achieved for the polyurethane elastomers of Nitro-HTPB as a novel energetic binder.