HTPB-III is a liquid, hydroxyl terminated polymer of butadiene with a number average molecular weight of approximately 2800. HTPB resins have primary, allylic alcohol groups that exhibit high reactivity in either condensation poly-merization reactions or the preparation of deriva-tives. The degree of polymerization is approxi-mately 50 for HTPB-III. Hydroxyl functionality is typically in the range of 2.2 to 2.4 for HTPB-III.