Effects of Ultrasonic and Physical-Rays Treatment on the Molecular Structures of Poly(γ-Glutamic Acid)

Abstract

Molecule structures of poly(γ-glutamic acid) (γ-PGA) were modified by ultrasonic, UV and 60Co γ-rays irradiation treatments, which might be used to prepare the polymer with low molecular weight. When 10 g/l γ-PGA solution was sonicated 60 times (400W, working time 3 s and interval 4 s) or that of 20 g/l solution was irradiated from 2 kGy to 10 kGy, the long-chain molecules were broken into smaller fragments. But, as the same solution of 10 g/l was irradiated by UV rays for 10 min, the molecular aggregates were observed in the solution so that the molecular weight distribution of γ-PGA became narrower compared with the control through the analysis of SDS-PAGE. These results would have a reference of the modification of γ-PGA molecules and the production of low molecular weight γ-PGA.