Self Assembly in Functionalized Butadiene Based Polyurethanes

Chemical modification of hydroxyl terminated polybutadiene (HTPB) oligomer without altering its inherent properties is achieved by covalently attaching various functional moieties such as 2, 4-dinitrophenyl (DNB) and triazine derivatives to the terminal carbons of HTPB. Fibrous self-assembly network formed by the hydrogen bonding through DNB groups is found to be the driving force for the unprecedented simultaneous improvement in both tensile strength and elongation in case of HTPB-DNB based polyurethane (PU). For example, tensile strength and elongation at break of the PU obtained using isophorone diisocyanate are found to be 1.21 MPa and 570.26%, respectively in case of HTPB-DNB whereas these values are 0.36 MPa and 91.22%, respectively in case of HTPB. In contrary, non hydrogen bonding supramolecular assembly of hard segment domains in triazine functionalized HTPB-PU resulted in reinforcement of mechanical strength and aggregation induced emission.