Synthesis and Antibacterial Activities of Quaternary Ammonium Salt of Gelatin

Abstract

Cationic proteins with tunable chemical and physical properties were prepared from 2,3-epoxypropyl trimethyl ammonium chloride (EPTAC) and gelatin. Measurement of grafting density indicated that the molar ratio of EPTAC/amine groups (NH2) in the gelatin chains played a key role in determining the compound's structure. Fourier transform infrared (FTIR) and 13C NMR results showed that the –NH2 functional groups of gelatin were totally consumed when the molar ratio of EPTAC/NH2 was increased to 2.5:1. Hydroxyl (‒OH) functional groups of gelatin were also depleted upon further increasing the molar ratio of EPTAC/NH2. Antibacterial activity and thermal properties of the product polymers changed with the modification of the polymers' structure.