One pot synthesis of bio-based porous isocyanate-free polyurethane materials

Abstract

In the current study, synthesis of porous isocyanate-free polyurethane materials derived from xylose is reported through a one-pot process, and the impact of varying amounts of crosslinker is studied. The synthesized materials were characterized using various techniques. The formation of the urethane bridge was confirmed using Fourier Transform Infra-Red (FTIR) spectra that exhibited characteristic bands around 1700 cm−1, 1600 cm−1, and 3400 cm−1. The characteristic peak observed at 21◦ (2θvalue) in Powder X-ray (PXRD) diffractogram further confirms the synthesis of segmented polyurethane porous materials. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) thermograms indicate that thermal stability and glass transition temperature (Tg) of synthesized non-isocyanate polyurethane (NIPU) materials increase with increase in the amount of crosslinker. The increase in Limiting Oxygen Index (LOI) values with an increment in the amount of crosslinker suggests improvement in flame retardant behavior of NIPU material due to formation of highly crosslinked network in the polyurethane matrix. These porous NIPU materials align well with the principles of sustainable development.