Synthesis and characterization of poly(urethane-imide)s with improved thermal stability

In this study, a new type of poly (urethane-imide) was synthesized via polycondensation polymerization technique.Polyurethane is synthesised by two-step reactions. First step prepolymer obtained from the reaction of 2, 4- diisocyanato-1-methyl-benzene (2, 4-TDI) with polyethylene adipate, then in second step prepolymer reacted with hydroxybenzene. Polyurethane prepolymer was mixed with poly (amide acid) and then films of this mixture were fabricated through casting method.The chemical composition of and thermal stability of synthesized product was analyzed by FT-IR and DSC respectively. Poly (urethane-imide) had shown good thermal stability as well as proper solvent resistance. It was observed that the glass transition temperature of fabricated films depends on the ratio of polyurethane and polyimide.

Keywords:

polyimide , polyurethane , poly (urethane-imide) , polyol , 4 , 4 diaminodiphenylether