Toughening agent for melamine formaldehyde resin: A new method for recycling chrome shavings

Considering the structural features of chrome-tanned collagen fibers (Cr-CF), the preparation of polymer modification fillers by using chrome shavings may be a feasible approach for the resource utilization of this tannery solid waste. Herein, Cr-CF from chrome shavings was used to modify the mechanical properties of melamine formaldehyde (MF) resin. Results proved that Cr-CF successfully toughened MF resin by intervening in the network polymerization and inhibiting the microcrack growth during material failure. The addition of 5 wt% Cr-CF powder that was prepared with an appropriate mechanochemical treatment enhanced the impact strength of MF resin by 324.4%, and increased the loss factor at 25 ? by 71.4%. These modification effects of Cr-CF were superior to those of other modification fillers. Therefore, the preparation of Cr-CF into toughening agent for thermosetting resin is a feasible method to achieve the effective recycling of chrome shavings.