液体石蜡对麦麸纤维/小麦麸质蛋白复合膜性能的影响

Effect of Paraffin Oil on the Properties of Wheat Gluten-Based Films Containing Cellulose

运用数学模型对复合膜的等温吸湿曲线进行拟合,研究液体石蜡对麦麸纤维/小麦麸质蛋白复合膜吸湿性能、透水性能的影响,并测定其机械性能和光学性能变化。结果表明,复合膜的等温吸湿动力学过程符合Peleg模型( R^2 >0.97, E <5%),GAB模型能精确模拟复合膜的吸附等温线( R^2 >0.99, E <5%)。添加5%~20%的液体石蜡可降低复合膜平衡吸湿率和水蒸气透过系数(water vapor permeability,WVP),提高复合膜的水接触角,其中添加15%的液体石蜡所制备的复合膜WVP降低了约47.8%,水接触角从54.2°提高至88.9°。添加液体石蜡同时降低了复合膜的抗拉强度(tensile strength,TS)、断裂延伸率(elongation at break,EAB)和透明度,加深了复合膜的色泽。添加15%液体石蜡的复合膜TS、EAB和透明度与对照相比分别降低了约49.1%、33.5%和71.6%。综合添加液体石蜡对复合膜的各项性能影响,推荐15%左右液体石蜡为适宜添加量。本研究结果可为液体石蜡/麦麸纤维/小麦麸质蛋白复合膜制备工艺参数的进一步优化提供参考。

In this paper,the influence of liquid paraffin on the moisture absorption and water permeability of wheat bran fiber/wheat gluten protein composite membrane was studied by fitting the isothermal moisture absorption curve of the composite membrane with mathematical model, and the mechanical and optical properties were detected. The results showed that the isothermal absorption kinetics of the composite films conformed to the Peleg model ( R^2 >0.97, E <5%), and the GAB model could accurately simulate the adsorption isotherm of the composite films ( R^2 >0.99, E <5%). The addition of paraffin oil at a level ranging from 5% to 20% could reduce the equilibrium moisture absorption rate and water vapor permeability (WVP) as well, which also improved the water contact angle of the composite films. Specifically, the WVP decreased about 47.8%, and the water contact angle increased from 54.2° to 88.9° with 15% addition of paraffin oil into composite films. The tensile strength (TS), elongation at break (EAB) and transparency decreased with the increase of paraffin oil in composite films. Compared with the control group, the TS, EAB and transparency of the composite films dropped about 49.1%、33.5% and 71.6% with 15% paraffin oil. Generally, the composite films obtained relatively good physical properties with 15% paraffin oil. The results of this study could provide reference in further optimizing the preparation parameters of wheat gluten-based films containing cellulose and paraffin oil.