Gelatin With Chitosan Blend Membrane Preparation And Modification Research

Chitosan polymers are the N-deacetylated derivative of chitin. Chitosan has a large number of amine and hydroxyl groups which may relate to the interaction between chitosan and many other materials.Through the interaction chitosan could be suitably modified to impart desired properties and distinctive biological functions. Chitosan have excellent film-forming performance, and it has many unique advantages, such as good biocompatibility, biodegradability, low toxicity, bacteria restraint and hygroscopicity. Because of that, the chitosan film has been used extensively in medical textile industry. Due to the chitosan that suitable for production is shortfall and expensive, the production and widely used of chitosan textile has been severely limited. Gelatin is a protein of animal origin, derived from the chemical degradation of collagen. Gelatin has excellent biocompatibility, nonantigenicity, plasticity, adhesiveness, and its potential to form hydrogen bonding with chitosan, gelatin was a suitable polymer blended with chitosan.This paper introduced the preparing of chitosan-gelatin modified films in different compositions by solution method. The firstly, Single factor test was applied to study the influence of the compositions of modified films, the temperature and concentration of coagulation bath, and the coagulating time on the mechanical properties, and the optimum technological conditions were determined. The results showed that the optimal blending ratio of Chitosan/Gelatin is70:30, the optimum temperature and concentration of coagulation bath are30℃and10%, the optimum coagulating time is60s. Then, according to the single factor, the level of the factors was decided and the orthogonal experiment design was prepared to determine the optimum process conditions of modified films.Mechanics behavior was studied on chitosan-gelatin modified films. The modificatory chitosan films have better fracture strength and breaking elongation. FT-IR was performed to characterize the chitosan films and modified films, study the molecular interactions between chitosan and gelatin in the blend films. XRD analysis indicated that the crystallinity of chitosan films decreased after modification. SEM, FT-IR, XRD and DSC analysis showed good compatibility between gelatin and chitosan. The water absorption and the water solubility of composite films were tested. With the increase of gelatin, the swelling ratio will decrease and then increase and the water solubility will increase.In order to improve the water solubility of chitosan-gelatin composite films, the tannins between1%vand20%acting as crosslinker was added to process tannin-gelatin-chitosan composite films. The structure and properties of the tannin-gelatin-chitosan composite films was characterized by FT-IR, SEM, XRD and DSC. The physical and machine properties, the swelling behavior and the water solubility were tested. It showed that the physical and machine properties of composite films exhibited little change, the water solubility have improved greatly.