Synthesis of polyurethane-urea from double CO2-route oligomers

Abstract

A series of thermoplastic polyurethane-ureas were synthesized from a soft segment of a polycarbonate diol and a hard segment of an oligourea, and both the segments were derived from the CO₂-route. The chemical structure of the synthesized segments and final polyurethane-ureas were identified by FT-IR and ¹³C-NMR. The average molecular weight of the oligourea was detected by potentiometric titration, MALDI-TOF and GPC. The M_n and M_w of the final polyurethane-ureas were nearly 0.7 × 10⁴ Da and 1.0 × 10⁴ Da, respectively, within a polydispersity index (PDI) of 1.27–1.44. Moreover, the X-ray diffraction (XRD) results showed that the as-synthesized polyurethane-ureas were amorphous and presented moderate thermo-stable properties with an initial decomposition temperature higher than 170 °C and a maximum decomposition temperature around 250 °C as examined by TGA. Furthermore, the amorphous polyurethane-ureas have a good solubility in some traditional organic solvents because the siloxane and carbonate groups were introduced into the main chain. The present novel polyurethane-urea, which possesses a high flexibility and fine compatibility with other polymeric materials, will have a wide application as a macromolecular plasticizer in plastic materials.