POSS-substituted hyperbranched polyester blends with thermoplastic polyurethanes

The aim of this research is to prepare and disperse in an elastomer a multi-branched form of POSS. Hyperbranched polymers (HBP) can be formed by grafting from a central core. POSS may be joined with a bifunctional reactant to form a bi-POSS joined by a single chain consisting of adipate (6C) or sebacate (10C). A hyperbranched polyester has been used as a core for attachment of multiple POSS molecules to create a large arrange of pendant POSS. The multi-POSS hyperbranched polyester core is a single molecule with polydispersity of branches and POSS attachments, so its mixtures with a polymer, in this case a thermoplastic polyurethane are technically blends, even though the POSS derivative may have the shape of a filler. Creep was retarded by the presence of multi-POSS. Recovery occurred with low permanent deformation, though the rate of recovery was decreased by the multi-POSS, which caused a greater skewness of the recovery curve deviating from exponential decay consistent with an increased distribution of relaxation times. The storage modulus increased with increase in the concentration of multi-POSS in the blends, while the damping factor was reduced