| Soybean hull is the by-product of soybean,which is used as feedstuff.In the process of producting they are abandoned and cause vast waste.Soybean hull contain 40% cellulose, 10% lignin, making use of this information can be used to solve the waste problem and increase the using range. Acetic acid nanofiber not only have better biocompatibility and plasticizer, but also have big specific area and high porosity. So acetic acid nanofiber will be the reaserch hotpoint of feed by-product copmprehensive utilization.This article was to make acetic acid nanofiber from soybean hull.The first of all was taking soybean skin as raw material for the synthesis of cellulose acetate. By researching on the amount of catalyst, reaction temperature, reaction time and other key controlling factors, to determine the technology and conditions of the synthesis of cellulose acetate.Characterizing their structure and properties and then to prepare cellulose acetate fiber by electrospinning. Through systematic analysis of the solvent, solution concentration, receiving distance and propulsion speed to know the influence on the morphology and diameter of electrospun cellulose acetate. The specific conclusions of the study are as follows:(1) The technology conditions of the synthesis of cellulose acetateTaking soybean skin as raw materials,using degree of polymerization(DP) as the evaluating parameter. Through the single factor and the Design-Expert response experiment to determine the technology conditions of the synthesis of cellulose acetate. The results show that :the amount of catalyst was 7%, the reaction temperature was 60℃, the solid-liquid ratio was 12 m L/g, reaction time of 3h were the optimum synthetic technology conditions. Under this condition, the degree of polymerization of cellulose acetate was 200.27. The degree of substitution was 2.83. Through the analysis of variance, the order of the significant level of four factors from high to low was reaction temperature >the amount of catalyst>solid-liquid ratio > reaction time.(2)The comparison of structure and properties of cellulose acetate with different degrees of acetylationBy controlling the reaction temperature of the synthesis of cellulose acetate, and carried on the comparative analysis of whiteness,transmittance, thermal stability, biodegradability and other properties.The analysis of whiteness and transmittance showed that with the increase of the reaction temperature, whiteness and transmittance of cellulose acetate decreased; Infrared spectrum analysis showed that the peak shape of the crude fiber of soybean skin and cellulose acetate were consistent,-OH band appeared in the vicinity of 3400cm-1, its peak area significantly decreased. C=O band appears in the vicinity of 1757cm-1, its peak area significantly increased. TGA analysis showed that with the increasing of the degree of substitution of cellulose acetate, the thermal stability increased. Biodegradability analysis showed that the smaller the degree of polymerization of cellulose acetate, the stronger ability of its degradation.(3)Preparation of cellulose acetate fiber of soybean skin by electrospinningTaking cellulose acetate of soybean skin as raw materials to prepare cellulose acetate fiber of soybean skin by electrospinning. Studying the influence of solvent, solution concentration, receiving distance,propulsion speed on the morphology of electrospun cellulose acetate. The solvent system results showed that with dichloromethane as solvent, the diameter of the relatively homogeneous "Ribbon" fiber was got. With chloroform as solvent, it was an almost "cubes" particles. With dimethyl sulfoxide as solvent, it could not form the fiber structure. Solution concentration results showed that the solution concentration was 7%, the fiber diameter was(36.7±3.76)μm and a large number of “bell shape”particles between the fibers. Solution concentration was 8%, the fiber was continuous, a diameter of(40.99 ±2.06)μm, but the fiber was uneven thickness. Solution concentration was 9%, fiber diameter was(50.9±2.83)μm, the fiber was continuous and uniform and fiber diameter distribution was more uniform.The receiving distance results showed that when the distance was 5 cm, the small fiber diameter was(39.34 ±3.26)μm, but the fiber was not continuous. The distance was 10 cm, the fiber was continuous and diameter mainly concentrated in the(49.78 ±4.58)μm range. The distance was 15 cm, the continuity of the fiber hadgood uniformity, but the fiber diameter was larger, it was(54.12 ±5.21)μm.The propulsion speed results showed that when keep a certain distance, the more propulsion speed, the greater the amount of solution,the larger diameter of the fiber, it was(43.96± 5.37)μm,(46.89± 4.87)μm, (47.03± 2.15)μm,(48.52± 3.18)μm, respectively. |
PDF Full Text Request