Synthesis and Investigation of Glycolysates and Obtained Polyurethane Elastomers

Abstract

The polyurethane (PU) intermediates were obtained by glycolysis of waste PU foam in the reaction with 1,6-hexamethylene glycol (HDO). The effects of different weight ratios of HDO to PUR foam on selected physicochemical properties were also determined. The polyurethanes were synthesized from the obtained intermediates by a two-step method using diisocyanate and a glycolysis product in the molecular mass range 700—1000. Hexamethylene glycol, 1,4-butylene, and ethylene glycol were used as chain extenders. The influence of the NCO group concentration in prepolymer on the glass transition temperature (Tg) and storage modulus of PU elastomers were investigated by the DMTA method. Thermal decomposition of the obtained glycolysates and polyurethanes was investigated by thermogravimetry coupled with Fourier transform infrared spectroscopy (FTIR). Tensile strength and elongation at break of polyurethanes were determined using Zwick universal tensile tester. FTIR spectra showed that main decomposition occurs at about 400°C in both glycolysates and PU elastomers. The main products of thermal decomposition are carbon monoxide, carbon dioxide, compounds containing ether and hydroxyl groups, and probably acetaldehyde. The synthesized PU’s had tensile strength in the range 13.4—15.6 MPa and elongation at break in the range 59.3—122.9%.