Abstract:

The acetylation process of silk protein for preparing a green and nutrition surfactant was investigated in this study. Some major technological parameters such as silk protein concentration, acetic anhydride amount, reaction temperature, reaction time, and pH were explored using orthogonal array design. The optimal values of the parameters were silk protein concentration 2%, acetic anhydride amount 15%, pH 8.5 and temperature 40 ℃ for a reaction duration of 20 min. Under these optimal conditions, the acetylation rate reached 47.8%. Acetylated silk protein surfactant was obtained through vacuum distillation and spray-drying. The structure of the product obtained was characterized by UV, IR and 1H-NMR spectra. After 10 days of storage, the biodegradability of acetylated silk protein surfactant was 98.9%. Therefore, the surfactant can be recognized as a biodegradable surfactant.

Key words: silk protein, acetylation, surfactant