Direct polymer grafting to surfaces and its application to interface tailoring in composites

Electrografting of different polymers directly on several materials is obtained (without a primary layer attached to the surface) (Surface-Polymer). This is achieved in the presence of a radical initiator, 2,6-dimethylbenzenediazonium. The initiator is easily reduced electrochemically, forming an aryl radical that triggers the polymerization of the vinylic monomer, without reacting on the surface, in a simple one step process; the polymeric chain reacts with the surface The different polymers that were tested include polymethyl methacrylate, poly1H,1H-perfluorooctyl methacrylate, polyglycidyl methacrylate, polyacrylic acid, poly(ethyleneglycol) diacrylate and vinylferrocene. IR, XPS, and electrochemical analysis provide evidence of successful surface functionalization. The electrografting of carbon fibers is of particular interest as it permits improving the mechanical properties of carbon-epoxy composites, it is chosen as an example to illustrate the reaction. The tensile strength and Young's modulus have slightly improved and a 73 % increase of the interfacial shear strength (IFSS) is observed.