Preparation and properties of new copoly(amide-imide-ether-urethane)s based on bis(p-amido benzoic acid)-N-trimellitylimido-L-leucine by two different polymerization methods

Two series of new optically active poly(amide-imide-ether-urethane)s (PAIEU)s based on polytetrahydrofuran (PTHF), of M-n=1000 as soft segment were synthesized. These copolymers were prepared via direct polycondensation reaction of an aromatic diacid based on L-leucine with preformed imide ring, 4,4'-methylene-bis-(4-phenylisocyanate) (MDI) and PTHF-1000. The effects of different reaction conditions and method of preparation (one-step vs. two-step method) on the physical properties of these new PAIEUs have been investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide angle X-ray scattering (WAXS), FTIR spectroscopy, and dynamic mechanical thermal analysis (DMTA). The effect of the introduction of bis(p-amido benzoic acid)-N-trimellitylimido-L-leucine (BPABTL) (1) into PU back-bone on their properties was also studied.