Synthesis of polyurethane-urea from double CO2-route oligomers

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 C-13-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 x 10(4) Da and 1.0 x 10(4) 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 degrees C and a maximum decomposition temperature around 250 degrees 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.