Improvement of heat resistance of high performance fibers using a cold plasma polymerization process

The aim of this work consisted in improving the heat barrier efficiency of different nonwovens (NW) to protect metallic substrates. The degradation of NW based on phenolic, melamine, polyacrylate, meta-aramid and polyimide fibers has been investigated by thermogravimetric analyses while the heat resistance of the NW has been evaluated by measuring temperature profiles in a heat radiator test. In order to decrease the surface emissivity and protect the fibers, a tetramethyldisiloxane (TMDSO) based plasma polymer has been coated on the NW surfaces using a Plasma Enhanced Chemical Vapor Deposition (PECVD) treatment. The plasma polymer has been characterized: it is composed of polysiloxanes, and the deposit coats homogeneously the surface fibers. Heat radiator tests carried out on the coated NW show that the organosilicon coating allows in most of the cases (phenolic, polyacrylate, meta-aramid and melamine NW) an effective improvement of the heat barrier effect under a radiative heat flux. The structural integrity of the NW under heating is improved as well, except in the case of polyimide based NW fabrics.