BYK C 8013 is a solvent-free polymeric coupling agent that increases the mechanical strength of carbon fiber-reinforced systems. BYK C 8013 was specially developed for use in carbon fiber-reinforced, radical-curing systems. The additive results in improved mechanical properties of the final part through increased fiber-matrix bonding. BYK C 8013 can be used with both vinyl ester- and epoxy-sized fibers. It is applicable in all radical-curing matrix resins. BYK C 8013 provides considerable increases in strength for hot-curing methods, such as SMC/BMC, pultrusion or RTM. The product enhances durability and load bearing capabilities of finished materials. BYK C 8013 improves structural integrity making finished goods more resilient to stresses and impacts over time.