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为开发低成本、高产能的可降解膜材料加工原料和制备工艺，探索了利用米糠加工副产物制备膜材料的技术途径。以米糠饼粕为原料制备多种米糠基制膜原料，再采用碱处理－湿法成膜工艺制备多种米糠基膜材料，比较不同米糠基膜材料的机械性能，优选出最佳的制膜原料，在此基础上对制膜助剂（交联剂与增塑剂）进行选择，采用正交试验优化膜制备工艺条件，并对其结构进行表征。结果表明：米糠压榨饼经醇洗得到的醇洗米糠（AWRB）全组分为最佳的制膜原料；以戊二醛（GA）为交联剂，甘油（Gly）为增塑剂制膜，AWRB全组分膜制备最优工艺条件为固液比1∶ 5、碱处理温度50 ℃、碱处理时间60 min、Gly用量10%（以AWRB质量计）、GA用量1.6%（以AWRB质量计），在此条件下所得AWRB全组分膜的拉伸强度为16.9 MPa，断裂伸长率为1.6%。结构表征结果显示，AWRB全组分膜的热稳定性较高，结构致密，无皲裂。AWRB中的多糖和蛋白质在GA交联作用下形成了热稳定性更高的网络结构；而不溶性的粗纤维及蛋白质起到协同增效作用，有效提升了米糠基膜材料的机械强度。AWRB全组分膜的原料制备无需复杂分离操作，且有望实现米糠制油、植酸提取及米糠基可降解膜的制备等米糠资源的全效利用。In order to develop low-cost, high-yield biodegradable membrane material processing raw materials and preparation process,a technical way was explored to prepare membrane materials by using rice bran processing by-products. With rice bran cake and meal as raw materials to prepare a variety of rice bran-based membrane raw materials, and then alkali treatment-wet film-forming process was used to prepare a variety of rice bran-based membrane materials. By comparing the mechanical properties of different rice bran-based membrane materials, the best membrane raw materials was obtained. On this basis,the film-making auxiliaries (cross-linking agent and plasticizer) were selected, and the orthogonal experiment was used to optimize the process conditions for the preparation of membranes, and the structure of membranes was characterized. The results showed that alcohol washed rice bran (AWRB) whole component obtained after alcohol washing of rice bran pressed cake was the best membrane raw materials. The optimal process conditions for the preparation of AWRB whole component membranes were obtained as follows: with glutaraldehyde (GA) as crosslinking agent, glycerol as plasticizer, solid-liquid ratio 1∶ 5, alkali treatment temperature 50 ℃, alkali treatment time 60 min, glycerol dosage 10%(based on the mass of AWRB), and GA dosage 1.6%(based on the mass of AWRB). The tensile strength of the AWRB whole component membranes was 16.9 MPa and the elongation at break was 1.6% under these conditions. Structural characterization results showed that the AWRB whole component membranes had high thermal stability, dense structure and no cracking. The polysaccharides and proteins in AWRB formed a network structure with higher thermal stability under the cross-linking effect of GA; insoluble crude fibers and proteins played a synergistic effect, which effectively improved the mechanical strength of the membranes. The raw material preparation of AWRB whole component membrane does not require complex separation operation, and it is expected to realize the full effective utilization of rice bran resources, such as oil production from rice bran, phytic acid extraction, and preparation of rice bran-based biodegradable membrane. |
