Thermo-mechanically improved curcumin and zwitterion incorporated polyurethane-urea elastomers

Abstract

Both polyurethane (PU) with natural bioactive moieties and zwitterion polymers are of increasing interest as a biomaterial, while their mechanical properties are still challenging. Our objective was to synthesize thermo-mechanically tunable PU with the incorporation of both zwitterion and natural bioactive moiety. In this work, a series of polyurethane-urea elastomers containing zwitterion and curcumin (ZCPUU) were synthesized by changing the molar ratio of Zwitterion diol (Z-diol) and curcumin (0.4:0, 0.3:0.1, 0.2:0.2, 0.1:0.3 and 0:0.4) keeping the constant molar ratio of hexamethylene diisocyanate (HDI), polycaprolactone (PCL) and chain extender 1,4-diaminobutane (DAB). Synthesized ZCPUU were analyzed by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), contact angle and scanning electron microscopy (SEM) to investigate the effect of Z-diol and curcumin on the properties of ZCPUU. TGA results revealed that ZCPUU with curcumin have better thermal stability. The properties of ZCPUU varied from 60 to 5 MPa for tensile strength, from 1585% to 171% for strain at breaking and from 22 to 2 MPa for initial moduli and 90-80% shape recovery at 40% strain. The hydrophilicity was decreased by increasing the curcumin. The surface morphology was characterized by SEM. Finally, the hydrolytic degradation stability was determined in phosphate buffer saline (PBS) at 37 °C. ZCPUU with an equal molar ratio of Z-diol and curcumin showed maximum stability in 8 weeks with only 5%–6% weight loss. These mechanically stable materials can be used as a potential biomaterial.