Experimental and Theoretical Investigation of Healable HTPB Based Polyurethanes by Furan/Maleimide Diels-Alder Reaction

The reversibility of the Diels-Alder reaction can be used advantageously in polyurethane materials to endow them with recyclable, thermally reversible properties and self-healing ability to expand their application range. In this paper, linear and crosslink polyurethanes based on HTPB, which exhibit thermal reversibility through Diels-Alder and retro Diels-Alder reactions, were prepared and characterized from reaction of bismaleimide and furan terminated polybutadiene. Also tetrafuran cross linker is synthesized and characterized by FT-IR and NMR for preparation of Diels-Alder network. Reversibility of Diels-Alder reaction was investigated through heating and cooling cycle by using differential scanning calorimetry (DSC). The results have shown that the retro Diels-Alder reaction is occurred at 150°C. Evaluation of healability of prepared polyurethane was done by cutting of polymer and recovering of its initial shape after reheating at 150°C.