Polymerization of organic compounds in an electrodeless glow discharge. X. Internal stress in plasma polymers

Abstract

Owing to the unique mechanisms operative in plasma polymerization, a thin layer of plasma polymer deposited on the surface of a substrate shows a tendency to expand, indicating an internal stress in the layer. This stress, σs, has been estimated from the observed curling of composite membranes in which the thickness of the plasma coating, d, is much smaller than the thickness of a flexible substrate, D, according to the relation where R is the radius of the roll into which the composite films curl up and E is the modulus of the substrate polymer. The stress σs is found to depend on the kind of monomer used and to be of the order of magnitude 108–109 dynes/cm2 with most of the monomers here employed.