Amine‐quinone polyurethanes. I. Preparation of polyurethane block copolymers containing 2,5–bis(N‐2‐hydroxyethyl‐N‐methylamino)‐1,4–benzoquinone diol monomer

Abstract

AbstractThe amine‐quinone monomer, 2,5–bis(N‐2‐hydroxyethyl‐N‐methylamino)‐1,4‐benzoqui‐none (AQM‐1), was prepared by the multiple‐step condensation of 2‐(N‐methylam‐ino)ethanol with benzoquinone in the presence of oxygen. This crystalline monomer was used to prepare a series of amine‐quinone polyurethanes by condensation polymerization, either in the melt or in solution (THF or DMF), with a diisocyanate (MDI, TDI, or IPDI) and an oligomeric diol [poly(caprolactone) or poly(1,2‐butylene glycol)]. The amine‐quinone functional group was stable under the polymerization conditions, and was incorporated into the main chain, giving red‐brown polyurethanes that had molecular weights in the range of 11,000–90,000 and were soluble in THF, MEK, DMF, and DMSO. The thermal properties were consistent with a two‐phase morphology with an amorphous soft segment, containing the oligomeric diol, and a microcrystalline hard segment, containing AQM‐1. The polymers having a low hard segment content (<50%) were rubbery (soft segment Tg <−25°C); polymers having a high hard segment content (>50%) were thermoplastic (hard segment Tg>150°C). © 1995 John Wiley & Sons, Inc.