TRANSFORMATION OF POLYMERS IN A STREAM OF LOW-TEMPERATURE ARC DISCHARGE PLASMA

摘要

Spraying of polymer materials in a low-temperature plasma stream is a very efficient way of depositing polymer coatings on large surfaces. The deposition of powdered polymers by an are discharge plasma flow and spraying from the bulk have been compared. The properties of powdered polymers do not change considerably during transportation by the stream because of the short residence of the particles in the plasma. When spraying from the bulk, polymers are transported in the form of melt droplets (polyethylene, polycarbonate) or in gaseous phase (polytetrafluoroethylene); autohesion of the droplets or secondary polymerization occurs, respectively, on the substrate surface. This process offers high-quality thin films and coatings whose structure depends significantly on the characteristics of the substrate as well as on the structure of the source polymer. Obtained polymer coatings contain nitrogen and oxygen entrapped from the atmosphere as well as (on the glass surface) the products of glass etching. This fact enables one to vary widely the properties of the coatings. Furthermore, the problem of obtaining combined protective coatings in which polymer melt fills the pores between metal particles can be solved successfully in a united technological cycle including plasma spraying of the polymer and the metal. (C) 1995 John Wiley & Sons, Inc. [References: 8]