Mathematical modeling and experimental study of mechanical properties of chitosan based polyurethanes: Effect of diisocyanate nature by mixture design approach.

This research work has been done to investigate the influence of the geometry of aliphatic diisocyanate (hexamethylene diisocyanate, HDI), cycloaliphatic diisocyanate (isophorone diisocyanate, IPDI) and aromatic diisocyanate (2,4-toluene diisocyanate, TDI) on the tensile strength and hardness of chitosan based polyurethane biomaterials. For this purpose, chitosan (CS) and polycaprolactone diol (PCL) based polyurethanes have been synthesized with above mentioned diisocyanates following statistical design (mixture design). Simplex mixture design was used for analysis and totally 10 experiments were generated by the software. Samples were tested based on the portions of mixture components. Fourier transform Infrared attenuated total reflection (FTIR-ATR) and nuclear magnetic resonance (NMR) spectroscopic techniques confirmed the synthesis of chitosan based polyurethanes. This biomaterial has been established as an innovative and promising strategy to improve the mechanical strength of chitosan-based polyurethanes.