ONE-POT SYNTHESIS OF SULFONIC ACID GROUP-CONTAINING HYPERBRANCHED POLYURETHANE

A novel sulfonic acid group-containing hyperbranched polyurethane was synthesized by the reaction of N-tris(hydroxymethyl) methyl-2-aminoethanesulfonic acid (TES) and isophorone diisocyanate (IPDI) with a one-pot method. The amino group of TES added selectively to the secondary isocyanate group of IPDI at low temperature (15 degrees C) to afford an AB(3) type monomer. The resultant AB(3) monomer could be polymerized in situ at high temperature (70 similar to 90 degrees C) to give hyperbranched polyurethanes. The degree of branching (DB), molecular weight and molecular weight distribution (MWD) of the hyperbranched polyurethane increased with increasing polymerization temperature. The number average molecular weight (M-n), MWD and DB of the polymer obtained at 90 degrees C were 22410, 3.36 and 0.87, respectively. The polymer electrolytes based on the obtained hyperbranched polyurethane sulphonate had good heat stability and high tensile strength. The temperature for 1% weight loss was more than 220 degrees C, and the tensile strength was up to 17 MPa. The ionic conductivity of the polymer electrolyte (lithium salt) was 3.1 x 10(-5) S/cm at room temperature (ca. 25 degrees C), 1.4 x 10(-3) S/cm at 100 degrees C