Journal of Bioresources and Bioproducts. 2018, 3(3) 107-111
Peer-Reviewed
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25,*,1$/3$3(5
Effect of microfibrillated cellulose (MFC) on the properties of gelatin based composite films
Shuaishuai Yang a , Haichao Li a , Huizhen Sun b
a) College of Chemistry and Chemical Engineering, Qinghai Nationalities University, Xining 810007, China. b) Center of Ecology Research, Northeast Forestry University, Harbin 150040, China. *Corresponding authors: li haichao@vip.163.com; sunhuizhen@hotmail.com
ABSTRACT
Properties of gelatin composite films ˄ with 4% glycerol as plasticizer ˅ with different mass concentrations of microfibrillated cellulose (MFC) (0.2-1.0%) were investigated. The prepared composite films with 1.0 % MFC showed the highest tensile strength (12.32 MPa) with the lowest water absorption rate (391.1 %). The composite films can be dissolved in hot water of 95°C in less than 5 minutes. However, the addition of MFC had insignificant effect on the heat shrinkage and light transmittance of the resultant composite films. Keywords: Gelatin films; Microfibrillated cellulose; Physicochemical properties 1. INTRODUCTION
the world and inexhaustible resources. 19,20 It is a micromolecular polysaccharide, which is composed of D- glucose with β -1, 4-glycosidic bond. The chemical formula is (C 6 H 10 O 5 ) n and the molecular-weight is about 5.0×10 4 -2.5×10 6 . Due to the existence of a large number of hydroxyl groups, which makes intermolecular and intramolecular of cellulose produce some strong hydrogen bond, and thus has an active effect on physical and chemical properties. In this paper, microfibrillated cellulose (MFC) was used to modify the dissolving and mechanical properties of gelation composite films, and the effect of MFC on the tensile strength (TS), Elongation at break, thermal and water adsorption properties was studied in detail. 2. EXPERIMENTAL 2.1. Material The gelatin was purchased from Tianjin Guangfu Fine Chemical Research Institute (Tianjin, China). MFC was procured from Sinopharm Chemical Reagent Co., Ltd (Shanghai, China). The glycerol was obtained from Tianjin Damao Reagent Factory (Tianjin, China). The gelatin was food grade and other agents were analytical grade, which were used without further purification. 2.2. Preparation of gelatin/MFC composite films The gelatin/MFC composite films were prepared by solution casting method as described. 21 For the preparation of composite films, 5 g gelatin was added into pure water (50 mL) with stirring until it dissolved completely. Then, 4% glycerol and 0.2-1.0% MFC were added and continued to mix at 60°C for 60 min in digital temperature control
Gelatin is a biodegradable polymer, which can be obtained by thermal denaturation or physical and chemical degradation of collagen. 1 Gelatin has excellent film-forming, biocompatible and biodegradable properties, 2, 3 which make it have a potential application in food packing. However, Gelatin dissolves easily in the 40°C solution, and its mechanical properties are also poor. Therefore, it is a research direction to seek a modification method to improve their dissolving and mechanical properties at present. The interest in gelatin has recently increased exponentially because of its biodegradable properties. Gelatin contains a large amount of hydroxyl, amino and carboxyl, which makes its modification method more diversified, such as physical, 4, 5 chemical 6, 7 and combining modification etc. 8, 9 For example, the gelatin composite films were modified with starch at different temperature, the results indicated that the crystallinity of the gelatin composite films could be increaseed. 10 The effect of stearic acid and reaction time on the properties of gelatin films were also investigated, and the results showed that the tensile strength and water absorption of the gelatin films decreased with the increase of stearic acid content. 11 The gelatin was modified by crossing-link with transglutaminase, and a bigger molecular weight could be obtained. 12 The modification of gelatin and gelatin-chitosan composite films with enzyme was also investigated, and the results showed that the viscosity modulus of gelatin-chitosan increased rapidly, and the effect on gelatin was not obvious. 13 Over the past decades, the study of cellulose composites was the most active one in the science and technology field. Cellulose is the main component of plan t’s cell wall, 14-18 which is the most abundant natural organic matter all over
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