Polyurethane elastomers-based modified castor oil and poly(ε-caprolactone) for surface-coating applications: Synthesis, characterization, and in vitro degradation

Polyurethanes (Pus) were synthesized from castor oil and modified through transesterification by pentaerythritol, poly(epsilon-caprolactone)diol (PCL), and isophorone diisocyanate to form PU coatings. The ratio of NCO/OH groups used was 1:1. The effect of varying the PCL content on the physical properties of wood panel PU coatings was determined. The PU coatings were characterized using Fourier transform infrared spectroscopic analysis, and the physicochemical properties, such as tensile strength, elongation at the break, shore A hardness, and the results of a lap shear test, were reported. Thermal properties of the PU coatings were evaluated using differential scanning calorimetry and thermogravimetric analysis. In vitro PU degradation was related to the hard segment structure and polymer hydrophilicity.