Low-temperature side-chain cleavage and decarboxylation of polythiophene esters by acid catalysis

Solubility switching of polymers is very useful in thin layer processing of conjugated polymers, as it allows for multilayer processing and increases the stability of the polymer. Acid catalyzed thermocleavage of ester groups from thiophene polymers carrying primary, secondary, and tertiary substituents have been examined by TGA-MS using different sulphonic acids. A substantial lowering of the cleavage temperature is observed, and the ester cleavage can even be performed in situ on roll-to-roll-coated films on polyethylene terephthalate (PET). (c) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012