A gaseous p-xylylene monomer, formed by reacting xylene with a monatomic oxygen source, is mixed with a functional gaseous monomer. The resulting mixture may be deposited and solidified on a substrate, which may optionally be exposed to a photoinitiating light energy and/or a permittivity enhancing electric or magnetic field. Alternatively, the resulting gaseous mixture may be trapped and condensed in a condenser, which may contain a solvent to facilitate trapping. The condensate may be mixed with a tertiary substance, e.g., another monomer, a reactive substance or an inert material.