Efficient green synthesis of bis(cyclic carbonate)poly(dimethylsiloxane) derivative using CO2 addition: a novel precursor for synthesis of urethanes

Abstract

Poly(dimethyl siloxane), PDMS, with terminal cyclic carbonate groups was prepared by cycloaddition of carbon dioxide to epoxy rings using tetra alkyl-ammonium bromide as a catalyst under efficient and mild conditions. The process was carried out under a modest pressure of carbon dioxide (i.e., <2 MPa) and temperature (<200 °C). The oligomeric species was found to be a non-Newtonian fluid with low molecular weight (MW ∼ 1200 g mol⁻¹) with n = xx − yy and thermally stable up to 200 °C. Its formation was verified by mid infrared spectroscopy (FT-MIR), Matrix-Assisted Laser Desorption Ionization Mass Spectroscopy MALDI-Tof-MS and multinuclear magnetic resonance (¹³C NMR, ²⁹Si NMR, ¹H NMR). The urethane synthesis was confirmed by FTIR, NMR and X-ray Photoelectron Spectroscopy (XPS) after reacting amines or diamines, in mild reactions conditions, with bis(cyclic carbonate)poly(dimethylsiloxane).