Structure versus hydrolytic and thermal stability of bio-based thermoplastic polyurethane elastomers composed of hard and soft building blocks with high content of green carbon

Abstract

AbstractNowadays, sustainability plays a key role in the design and synthesis of new materials. One of the methods for the preparation of green materials is incorporation into their structure the monomers with a high content of green carbon. Therefore, the aim of this work was to investigate the influence of the type and molecular mass of two bio-based polyester polyols and bio-glycol on the properties of aliphatic partially bio-based thermoplastic polyurethane elastomers (bio-TPU). Two series of bio-TPUs materials composed of hard and soft building blocks with high green carbon content were prepared via the two-step method (prepolymer method). Two amorphous bio-based polyester polyols with the molecular mass ~ 2000 (P1) and ~ 3000 (P2) were used. Bio-TPUs were prepared at three different molar ratio of [NCO]/[OH]: 0.9, 0.95, and 1.0. In order to determine the influence of bio-based polyols and the content of hard segments on the properties of bio-TPU, relevant test methods were used. The Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetry (TG) revealed hydrolytic and thermal stability of bio-TPUs. Viscoelastic behavior, mechanical and physical properties were examined in terms of dynamic mechanical thermal analysis (DMTA), tensile test, hardness, and density. Analysis of the measurement results confirmed the significant influence of the molecular mass of the bio-based polyols and the molar ratio of [NCO]/[OH] on the bio-TPUs properties. Due to good mechanical properties, low density, and thermal stability up to 300 °C, the obtained materials can find many useful applications. This issue is essential in terms of sustainable development and reduction in the CO2 emissions to the atmosphere.