Quinone-amine polyurethanes: New coupling agents for the steel-epoxy system

A new series of quinone-amine polyurethanes (QAPs) were synthesized using t oluene diisocyanate, polytetrahydrofuran, and an amine-quinone monomer (AQM 1). The AQM1 was synthesized and characterized using spectroscopic techniqu es (UV, IR, NMR). The QAP synthesis involved a two-step process and yielded block copolymers. These polymers were characterized using infrared spectro scopy, thermal analysis methods (thermogravimetric analysis and differentia l scanning calorimetry) and gel permeation chromatography. Steel coupons we re treated with dilute solutions of the QAPs and analyzed using surface spe ctroscopic techniques (X-ray photoelectron spectroscopy, infrared reflectio n spectroscopy). These tests indicate that the polymer shows chemical inter actions with the steel surface. The QAPs were tested for their efficiency a s polymeric coupling agents to enhance the adhesion of steel to epoxy. The coupling agent treated epoxy-steel torsional joints were tested in shear. T hey demonstrated 10 -15% dry strength improvement when compared to steel- e poxy controls. The QAPs can serve as very effective coupling agents for the steel- epoxy system. (C) 2000 John Wiley & Sons, Inc.