微晶纤维素/明胶对淀粉复合薄膜性能影响研究

Effect of microcystalline cellulose/gelatin on the properties of starch composite films

探究微晶纤维素/明胶对淀粉复合膜热封、力学、热稳定性能等影响,以期提升淀粉基薄膜的综合性能。以不同比例微晶纤维素/明胶(1∶9,2∶8,3∶7)做增强相,溶液浇铸法制备多组分淀粉膜—微晶纤维素/明胶/淀粉膜(MCC/GL/ST)。通过扫描电镜(SEM)、差示量热扫描(DSC)、热重分析(TG)对薄膜进行表观形貌及热稳定性分析,采用热封仪、万能材料拉力机表征薄膜力学性能、热封性能。结果表明,与微晶纤维素/淀粉膜(MCC/ST)相比,微晶纤维素/明胶(2∶8)/淀粉膜(MCC/GL/ST-2)热封强度提高了352.9%,拉伸强度提高至9.12 MPa,红外光谱分析(FT-IR)表明MCC和GL之间存在氢键相互作用;薄膜阻隔性能随明胶添加量降低而提升,DSC及TG曲线表明MCC/GL/ST-2具有良好的热稳定性,可满足热封加工性的同时保证其性能稳定。

The work aims to explore the effects of microcrystalline cellulose/gelatin on heat sealing,mechanics and thermal stability performance of starch composite films with a view to improving the comprehensive properties of starch-based films.In this study,microcrystalline cellulose/gelatin(MCC/GL)was used as enhancement phase to prepare microcrystalline cellulose/gelatin/starch film(MCC/GL/ST)by solution casting method.Scanning electron microscopy(SEM),X-ray diffraction(XRD),differential scanning calorimetry(DSC),and thermo gravimetric analysis(TG)were used to analyze the films of apparent morphology and thermal stability,and the mechanical properties and heat sealing properties of starch films were characterized by heat sealing instrument and universal material tension.The result shows that compared with that of microcrystalline cellulose/starch film(MCC/ST),in microcrystalline cellulose/gelatin(2∶8)/starch film(MCC/GL/ST-2),heat sealing strength was increased by 352.9%and tensile strength was increased to 9.12 MPa.Infrared spectroscopy(FTIR)shows that there is a hydrogen bond interaction between MCC and GL,and the film barrier performance improves with the decrease of gelatin addition.The DSC and TG curves show that MCC/GL/ST-2 has good thermal stability,which can meet the heat sealing processability and ensure its stable performance.