Desenvolvimento e caracterização de biofilmes de sericina reticulados com dimetiloluréia

Abstract

Sericin is a natural silk protein, which is removed from silk in a process called degumming. There are, in the Bombyx mori silkworm cocoon, two different proteins: fibroin, that represents 70-80% of total weight and sericin with that 20-30% remaining. Its application vary with its molecular weight: high molecular weight peptides are used in medical and biodegradable biomaterials, functional fibers, hydrogels and others;low molecular weight peptides are commonly used in cosmetics industry. The objective of this study was the preparation and the characterization of films formed from high molecular weight sericin, analyzing the influence of glycerol as plasticizer and dimetiloluréia as crosslinking agent in respect of their mechanical properties, water vapor permeability and solubility in water. The addition of glycerol promoted a significant increase in moisture content of sericin films with the same degree of crosslinking, while a decrease in tensile strength and modulus was observed.The chemical modifications by adding dimetiloluréia were effective in decreasing the permeability to water vapor, effect caused by the introduction of stable covalent bonds between the reactive groups present in sericin chains.