CHARACTERIZATION OF ELECTROPOLYMERIZED GRAPHITE FIBER POLYACRYLAMIDE COMPOSITES

The synthesis of a series of graphite fiber-polyacrylamide composites was performed electrochemically in dilute sulfuric acid (0.125M) -acry lamide (2M) solution, 1 : 1 sulfuric acid (0.25M) : acetone-acrylamide (2M) solution, and 1 : 1 sulfuric acid (0.25M) : 2-propanol-acrylamid e (2M) solution, respectively, using graphite fiber bundles as the wor king electrode. The graphite fiber-polyacrylamide composites, synthesi zed in a 1 : 1 2-propanol : sulfuric acid-acrylamide solution, were mo re easily characterized than those synthesized from the sulfuric acid- acrylamide solution that contained no alcohol. Composites that were sy nthesized in a dilute sulfuric acid solution were, however, more readi ly crosslinked. (Fourier transform infrared spectroscopy, FTIR, confir med the formation of interchain and intrachain imide functional groups after the resin was cured at approximately 200-degrees-C.) Polymer we ight gain analysis, coupled with surface morphology studies using scan ning electron microscopy, showed that the thickness of the coatings, a nd hence the volume fraction of the resin in the composites, varied li nearly with the time of electropolymerization. Scanning electron micro scopy revealed an open and folded chain surface structure, which permi tted unrestricted permeation of the monomer onto the electrode surface . Differential scanning calorimetry of the electropolymerized resins c onfirmed a glass transition temperature of between 180 and 207-degrees -C. (C) 1994 John Wiley & Sons, Inc.