The role of hydrogen bonding on tuning hard-soft segments in bio-based thermoplastic poly(ether-urethane)s

This work describes the preparation of bio-based thermoplastic poly(ether-urethane)s (TPU) via a prepolymer method and investigates the effect of varying the interphase hydrogen-bonding (H-bonding) on physicochemical, thermal and mechanical properties. This was achieved by varying the glycol type and molar ratio of [NCO]/[OH] groups used during the prepolymer chain extending step. The TPUs' chemical structure was analyzed by Fourier Transform Infrared Spectroscopy (FTIR-ATR) spectroscopy, the H-bonding fraction and crystallinity were examined by FTIR, Different Scanning Calorimetry (DSC), X-ray diffraction (XRD) and Polarized light optical microscopy (POM), and their processability was surveyed using the melt-flow index and Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF-MS). Moreover, a coupled- Thermogravimetric analysis (TGA)-FTIR method provided useful information about thermal degradation and low molecular mass volatile products formed during the TPUs' thermal decomposition. Altogether, this study intends to provide engineers with new insights to obtain environmentally friendly TPU-based polymeric components (from prime materials to process methods), by associating the application of bio-based reactants to the TPU synthesis and understanding the conditions for these bio-TPUs been applied in low-waste processes such as additive manufacturing. (C) 2020 Elsevier Ltd. All rights reserved.