Repeated Catalytic Main Chain Scission

Polycarbonates based on 2-cyclohexen-l,4-diol and a dihydroxy compound liberate benzene through aromatization, a dihydroxyl compound, and carbon dioxide, upon acidolysis [343]. The low volatility of the dihydroxyl compound hampers complete development by heating alone and necessitates wet development. 

Polyformals containing secondary allylic and benzylic groups undergo complete acidolytic decomposition to volatile products such as an aromatic com- 

This catalytic main chain scission has been revisited recently in an attempt to reduce LER and outgassing but high resolution imaging or the validity of the concept has not been demonstrated [344]. 

Polyethers consisting of alkoxypyrimidine units undergo an acid-catalyzed tautomeric change from the alkoxypyrimidine to pyrimidone, releasing dienes (Fig. 112) [345]. 

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