Cycloaddition approach to the curing of polyimides via precursor containing thiophene‐S,S‐dioxide

A new method for linear polymerization of maleimides via the Diels–Alder reaction has been developed. This method involves use of a new cross‐linking agent, benzene‐3,4‐dimethylenesuccinimide, which can be generated in situ from its thiophene precursor, benzene‐2,5‐dihydrothiophene‐3,4‐dicarboximide‐S,S‐dioxide. This new cross‐linking agent is reasonably reactive, readily prepared, and stable at room temperature. A controlled molecular weight oligomer has been synthesized and applied to the polymerization to yield a highly thermal stable polyimide. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:648–652, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20249