Poly(p-xylylene) and its derivatives by chemical vapor deposition: Synthesis, mechanism, and structure

Poly(p-xylylene) (PPX) and its derivatives were prepared by vapor-phase pyr olysis and subsequent chemical vapor deposition (CVD) of the pyrolysis prod ucts. Readily available esters of alpha,alpha'-dihydroxy-p-xylylenes were u tilized as starting materials. Mechanistical studies prove that 1,4-quinodi methane is formed by pyrolysis of diesters. The PPXs obtained compare well to PPXs obtained by the classical route using [2.2]paracyclophanes. C-13 CP -MAS NMR spectroscopy indicates that the arrangement of substituents along the polymer main chain is controlled by the size of substituents.