Sustainable starch modified polyol based tough, biocompatible, hyperbranched polyurethane with a shape memory attribute

In recent years, application of shape memory polymers (SMPs) has gained substantial impetus in the design of improved and minimally invasive smart biomedical implant devices based on their thermal response behavior. In this direction, the authors designed a tough, biodegradable and biocompatible shape memory hyperbranched polyurethane (HPU) suitable for use in medical implant devices. HPUs with three different compositions containing 11, 14 and 17 wt% of starch modified polyol as the branch generating moiety were synthesized via an A(x) + B-y (x, y >= 2) approach, without the use of any plasticizer or catalyst. The structures of the synthesized HPU were confirmed from FTIR, NMR and various analytical studies. The biodegradable HPU exhibited combined attributes of remarkable mechanical properties (17 MPa tensile strength, 1450% elongation at break, 6.5 kg scratch hardness, >100 cm impact strength and 163 MJ m(-3) toughness) at room temperature and the desired shape memory behavior (98.8% shape fixity and 98.9% shape recovery) at around body temperature (37 +/- 1) degrees C. Also, no significant change in mechanical performance was observed under wet conditions. Moreover, cell proliferation and live/dead cell viability assays confirmed the biocompatibility of the synthesized HPU. Thus, the overall results indicated its potential application as an advanced material in the biomedical field.