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 pyrolysis and subsequent chemical vapor deposition (CVD) of the pyrolysis products. Readily available esters of α,α‘-dihydroxy- p -xylylenes were utilized as starting materials. Mechanistical studies prove that 1,4-quinodimethane is formed by pyrolysis of diesters. The PPXs obtained compare well to PPXs obtained by the classical route using [2.2]paracyclophanes. 13 C CP-MAS NMR spectroscopy indicates that the arrangement of substituents along the polymer main chain is controlled by the size of substituents.