Synthesis and Characterization of New Polyimides Having Noncoplanar Biphenylene Moieties

Polyimides are a class of polymers that have been used extensively in microelectronics and in a variety of advanced technologies. The studies of these materials have mainlyfocused on the electronics, coating, composites, gas separation, and fiber applications [1]. Although exceptionalthermal stability is complemented by excellent mechanicaland electrical performance, their insolubility in common organic solvents and their high glass transition and softeningtemperatures make these systems difficult to process and fabricate. A variety of structural modifications to thepolyimide backbone, such as bulky substituents [2],noncoplanar biphenylene moieties [3], and flexible [4] and kinked [5] units, can be employed to modify the polymer properties