The preparation and application of polycyanogen and polyazomethine polymers

This work was undertaken with two objectives in mind. Firstly polycyanogen (PCN) and polyazomethine (PAZ) polymers were examined as precursor candidates for carbon fiber preparation. From thermal analyses, both polymers show good thermal stability and a relatively high yield of carbon residue. Although there are serious obstacles in processing them into homogenous fiber form, the research results indicate that both polymers exhibit promising potential.; Secondly, both polymers were investigated as interfaces for the carbon fiber in a reinforced aluminum (CFRAL) composite. The goal was to improve compatibility while sustaining the mechanical strength of the CFRAL composite. The PCN and PAZ polymers can be carbonized and graphitized by a series of heat treatments. Improvement in the interface between a carbon fiber and a metal matrix was obtained by this method of delivering metal atoms to the surface in a disordered carbon layer.; We performed a detailed study of the mechanical properties of coated carbon fibers and composites as a function of different polymer-metal complex coating solutions and post-preparation heat treatment protocols. Four different polymer-metal solutions were elected for study that involved the combinations of PCN or PAZ polymers with AlCl{dollar}sb3{dollar} and TiCl{dollar}sb3{dollar}. In all cases we obtained well coated carbon fibers with a coating thickness of about 0.1 {dollar}mu{dollar}m. These coated fibers were then further coated with aluminum metal by either a vacuum deposition process or by dipping into an Al melt. The carbon fiber-aluminum composite wires were then reheated to 700{dollar}spcirc{dollar}C to simulate metal matrix composite processing conditions. The mechanical properties of the coated fibers and composite wires at each fiber treatment step were evaluated. Scanning electron microscopy and wetting measurements using a Wilhelmy balance were performed to assist in characterization of the coated fibers.