School of Chemical and Bio-Engineering, Institute of Technology, Addis Ababa University, P.O Box 385, King George VI Street, Addis Ababa, Ethiopia; Department of Chemistry, College of Natural Science, Colorado State University, 301West Pitkin Street, Fort Collins, CO 80523, USA.
School of Chemical and Bio-Engineering, Institute of Technology, Addis Ababa University, P.O Box 385, King George VI Street, Addis Ababa, Ethiopia.
Int J Biol Macromol. 2020 Jul 15;155:581-587. doi: 10.1016/j.ijbiomac.2020.03.218. Epub 2020 Mar 28.
Anchote (Coccinia abyssinica) starch films were prepared by a solution casting method with glycerol, 1-ethyl-3-methylimidazolium acetate, sorbitol or triethylene glycol as plasticizers. The effect of these plasticizers and their concentration on film microstructure, thermal, and mechanical properties was investigated. Scanning electron microscopy revealed that regardless of plasticizer type, films possessing higher plasticizer content had more homogeneous morphologies than those with lower plasticizer content. The FTIR spectra of films plasticized with 1-ethyl-3-methylimidazolium acetate had higher intensity peaks at 3150, 1400 and 1000 cm when compared to other film peaks. These data show that 1-ethyl-3-methylimidazolium acetate plasticized films have decreased molecular order which results in less hydrogen bonding. For this reason, films developed from 1-ethyl-3-methylimidazolium acetate were more flexible than the others. The effect of plasticizers on the thermal properties of the anchote starch films was investigated using thermogravimetric analysis (TGA). Films made from 30% (w/w) plasticizer concentration exhibited higher thermal stability for all types of plasticizer. Mechanical testing showed that sorbitol films had the highest tensile strength, approximately 2 times that of the triethylene glycol plasticized film and 3 times that of the film made from 1-ethyl-3-methylimidazolium acetate.
用溶液浇铸法制备了可可酰淀粉膜，其中甘油、1-乙基-3-甲基咪唑醋酸盐、山梨糖醇或三乙二醇作为增塑剂。研究了这些增塑剂及其浓度对薄膜微观结构、热性能和机械性能的影响。扫描电子显微镜表明，无论增塑剂的类型如何，具有较高增塑剂含量的薄膜比具有较低增塑剂含量的薄膜具有更均匀的形态。与其他薄膜峰相比，用 1-乙基-3-甲基咪唑醋酸盐增塑的薄膜的 FTIR 光谱在 3150、1400 和 1000 cm 处具有更高的强度峰。这些数据表明，1-乙基-3-甲基咪唑醋酸盐增塑的薄膜具有较低的分子有序性，从而导致氢键减少。因此，与其他薄膜相比，用 1-乙基-3-甲基咪唑醋酸盐制备的薄膜具有更好的柔韧性。使用热重分析（TGA）研究了增塑剂对 anchote 淀粉膜热性能的影响。对于所有类型的增塑剂，在 30%（w/w）增塑剂浓度下制成的薄膜表现出更高的热稳定性。力学性能测试表明，山梨糖醇薄膜具有最高的拉伸强度，大约是三乙二醇增塑薄膜的 2 倍，是 1-乙基-3-甲基咪唑醋酸盐增塑薄膜的 3 倍。
