Protein-polymer hybrid oil-absorbing gel using hair keratin as macroinitiator by SET-LRP

Biological macroinitiator for single electron transfer-living radical polymerization was designed from extracted human hair keratin by nucleophilic reaction of amino group with 2-bromoisobutyryl bromide. Homogeneous polymer-protein hybrid oil-absorbing gel was synthesized by copolymerization of acrylate with a small amount of cross-linker using keratin-Br macroinitiator. The variation of gelation properties including gelation time, gel fraction and oil absorbency was studied by changing monomer composition, initiator type, and cross-linker structure. The gelation time did not change significantly by varying the substitution degree of macroinitiator. Aromatic cross-linker was more prone to form microgel and higher oil absorbency was achievable with longer oleophilic chain of acrylate. The polymer-protein was obtained with the maximum oil absorption of chloroform reaching 43.7 g g−1 and performed good reusability.