Synthesis and characterization of urethane polymers containing 2,2′‐biimidazole

Abstract

A heterocyclic nitrogen‐containing system having substituent primary diol function, i.e., 1,1′‐dihydroxethyl‐2,2′‐biimidazole (I), has been prepared and used to synthesize a series of new polyurethanes based on aromatic diisocyanates (TDI, MDI). Variation of solution polymerization parameters permitted the isolation and infrared, NMR, molecular weight, and thermal characterization of polymeric materials. Isolated polymers exhibit a linear structure and have T_g (150–170°C) and thermal stability (205–250°C for 20% weight loss) properties comparable to other typical urethane polymers. Zn²⁺ complexation was indicated by shifts in the imidazole ringmode infrared vibrational bands at 917 and 1133 cm⁻¹ to higher frequencies.