Abstract:

In order to prepare water-absorbing composite of fibroin/acrylamide/acrylic acid with better biocompatibility and biodegradability, silk fibroin was introduced into the conventional water-absorbing composite of acrylamide/acrylic acid. To obtain active free radicals on silk fibroins, UV irradiation was used to activate fibroin molecules via binding hydrogen of phenolic group of tyrosine residues and alcoholic hydroxyl in serine residues. Thus, the graft copolymerization of AM and AA with silk fibroins was carried out. The composite membrane of fibroin/AM/AA were prepared by freexe-drying method. The changes in the molecular weights of fibroin materials, structure characteristics, thermal characteristics and surface morphologies of the composite fibroin emebranes under fifferent treating conditions were investigated, respectively. The water absorption and comservation properties and conservation peoperties and repeated water-absorbing performance were also evaluated. The results indicate that AM and AA are successfully grafted and copolymerized onto fibroin surfaces, leading to an increase to an increase of molecular weight of fibroin proteins. The structure characteristic of vinyl disappeared in the composite material and improved thermal stability is achieved. Meanwhile, acceptable water swelling and conservation properties along with repeated water absorption capabitity for the composite membrane are also obtained.

Key words: UV irradiation, silk fibroin, acrylamide, acrylic acid, water-absorbing composite