The use of synthetic plastic films has raised several environmental issues. The use of bioplastics is therefore expected as an alternative. In this study, sorghum grain extract was explored as the source for bioplastic films considering the prediction of massive availability of sorghum grains as by-products of bioethanol production. Sorghum grain extracts are rich in carbohydrate and protein, the two principals of bioplastic making. Therefore, the ability to re-utilize sorghum grain extracts is further expected to reduce the production cost. In addition to sorghum grain extracts, additives were involved in the process, which were carrageenan and sorbitol. Carrageenan was used as a gelling agent during the bioplastic’s productions while sorbitol was involved as the plasticizer. The effect of sorbitol and the ratio of sorghum extract to carrageenan on the physical and mechanical properties of the bioplastic film were investigated. The concentration of sorbitol was varied at 0, 2, 4, and 6%; the ratio of sweet sorghum extract to carrageenan was varied as 5:5, 6:4, 7:3, and 8:2 at sorbitol concentration of 4%. The alkaline method was used to solubilize milled sorghum grain. The solution casting method was used to produce the bioplastic film. The film thickness was dependent on the concentration of the sorghum extract. The sorbitol incorporation reduced the tensile strength of the film while the concentration of the sorghum extract did not significantly alter the tensile strength. Improved flexibility was observed as the sorbitol concentration was increased. Water vapor transmission rate of the films is in the range of 100–147 g/m² day, lower than polymethylpentene (PMP), a polyolefin petroleum-based plastic film, indicating the potential of the bioplastic films for future application. This further indicates the possible biorefinery of sorghum by-products as raw materials for bioplastic production.

合成塑料薄膜的使用引起了一些环境问题。因此，期望使用生物塑料作为替代。在这项研究中，考虑到对高粱谷物作为生物乙醇生产副产品的大量利用的预测，高粱谷物提取物被用作生物塑料薄膜的来源。高粱谷物提取物富含碳水化合物和蛋白质，这是生物塑料制造的两个主要原理。因此，进一步期望重新利用高粱谷物提取物的能力以降低生产成本。除了高粱谷物提取物外，还加入了角叉菜胶和山梨醇等添加剂。在生物塑料的生产过程中，角叉菜胶被用作胶凝剂，而山梨醇被用作增塑剂。研究了山梨糖醇和高粱提取物与角叉菜胶的比例对生物塑料薄膜物理机械性能的影响。山梨糖醇的浓度在0、2、4和6％范围内变化；山梨糖醇浓度为4％时，甜高粱提取物与角叉菜胶的比例为5：5、6：4、7：3和8：2。碱性方法用于溶解磨碎的高粱谷物。使用溶液流延法生产生物塑料膜。膜厚度取决于高粱提取物的浓度。山梨糖醇的掺入降低了膜的抗张强度，而高粱提取物的浓度并未显着改变抗张强度。随着山梨糖醇浓度的增加，观察到改善的柔韧性。^第2天低于聚烯烃石油基塑料薄膜聚甲基戊烯（PMP），表明该生物塑料薄膜在未来的应用潜力。这进一步表明可能将高粱副产物作为生物塑料生产的原料进行生物精制。