Plasma Polymerization of Acetylene: A Coating Technique for Fibre Reinforcement of Composites

Abstract

In this work, the plasma polymerization is applied as a versatile method for controlled deposition of polymeric films to create a reactive fibre surface. Films of different composition were deposited continuously on carbon and glass fibres using the r. f. sputtering technique and acetylene/air mixtures as reactive gases. The plasma polymeric films were characterized by IR-spectroscopy, gas phase analysis while depositing, X-ray photoelectron spectroscopy, elemental analysis, thermogravimetric analysis and contact angle measurement. The influence of polymer layer thickness on mechanical data such as tensile strength, Young’s modulus and strain to failure of single fibres was investigated. To examine the fibre/matrix adhesion, composites of different carbon fibres and epoxy resin were manufactured. The interlaminar shear strength (ILSS) is found to be about 25% increased for the coated fibres in the composites. So it should be concluded that the reactive chemical groups are responsible for the improvement of the fibre/matrix adhesion according to the acid/base concept.