Journal of Polymer Science Part A: Polymer Chemistry, Vol.33, No.17, 2881-2886, 1995
Amine-Quinone Polyurethanes .1. Preparation of Polyurethane Block-Copolymers Containing 2,5-bis(N-2-Hydroxyethyl-N-Methylamino)-1,4-Benzoquinone Diol Monomer
The amine-quinone monomer, 2,5-bis(N-2-hydroxyethyl-N-methylamino)-1,4-benzoquinone (AQM-1), was prepared by the multiple-step condensation of 2-(N-methylamino)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 T-g < -25 degrees C); polymers having a high hard segment content (>50%) were thermoplastic (hard segment T-g > 150 degrees C).