Thermal and dynamic mechanical characterization of polyurethane-urea-imide coatings

摘要: A series of NCO terminated polyurethane (PU)–imide copolymers were synthesized by a systematic three-step process and chain extended with different diol/diamine extenders. In the first step, isocyanate PU prepolymers prepared reacting soft segments such as polyester (PE) polyols polyether polypropylene glycol (PPG-1000) hard like 2,4-tolylene-diisocyanate (TDI) or isophorone-diisocyanate (IPDI) NCO/OH ratio 2:1. second thermally stable heterocyclic imide ring was incorporated using pyromellitic dianhydride (PMDA) in excess-NCO:anhydride 1:0.5. The surplus content after imidization both moisture cured partially reacted extender cured. films characterized thermogravimetric (TG), differential scanning calorimetry (DSC) dynamic mechanical thermal analysis (DMTA) instruments. adhesion strength these coatings on mild steel (MS), copper (Cu), aluminum (Al) is dependent nature substrate. TGA show good stability. DMTA results microphase separation between segments. Finally, structure to property correlation drawn based soft, hard, observed properties are useful for understanding design intelligent coatings. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3158–3167,