Synthesis and mechanical properties of hyperbranched polyether/HTPB polyurethane based IPN

Cationic ring-open polymerization was used to synthesis hydroxyl terminated hyperbranched polyether. The end-groups of hydroxyl were modified for tailor the compatibility of hyperbranched polyether with hydroxyl terminated polybutadiene. The structures of resultant polymers were characterized by FT-IR and 1H-NMR. Hydroxyl terminated polybutadiene and isophorone diisocyanate were cured at the existence of hyperbranched polyether to generate hyperbranched interpenetrating polymer network. Mechanical property tests indicated that while the modified hyperbranched polyether adds into hydroxyl terminated polybutadiene polyurethane elastomer, its tensile strength and elongation improve obviously. Specially, when modified hyperbranched polyether of generation 4 rises up to thirty percentage of the whole weight, the resultant elastomer has the best tensile strength and elongation, which increases 3. 86 times and 3.7 times than pure hydroxyl terminated polybutadiene polyurethane elastomer, reaches 2.65 MPa and 1868% respectively.