淀粉基膜材料的制备与性能研究

发布时间：2019-05-05 09:31

【摘要】：作为最常见的一种可再生天然高分子原材料,淀粉具有成本廉价、来源广泛的优点。我国淀粉资源储量丰富,淀粉产品及相关产业的研究和创新关系着农业、食品工业、医药等行业的发展。研究不同来源淀粉的结构、特性,扩大变性淀粉的类型、改进淀粉改性方法,研制其与不同物质的复合材料制备工艺及性能,是实现淀粉产品开发和利用的基础。在石油资源短缺、环境日益恶化的今天,以丰富廉价、可再生的淀粉为原料制备淀粉基复合材料,用以代替石油基塑料材料具有极大的现实意义和应用价值。通过对淀粉认识的加深和对添加剂、改性方法的不断研究,有助于可完全降解、绿色环保、价格低廉、性能优越的淀粉基新型功能材料的制备,并实现其广泛应用。本论文从淀粉膜材料自身力学性能不佳的缺陷入手,在对淀粉、增塑剂、增强剂结构等因素与力学性能关系的研究基础上,制备了淀粉基植物医用硬胶囊和改性石墨烯-淀粉自组装复合膜材料。通过对制膜工艺过程中不同种类的淀粉进行结构、胶液和膜材料性能的对比,掌握了原淀粉和改性淀粉性能之间的差异,对各种淀粉膜材料强度、溶胶黏度等有了具体认知;此外,研究了制膜工艺中溶胶黏度、塑化剂含量、凝胶剂、增强剂种类等因素,对淀粉基复合型膜材料的抗拉伸强度、水阻隔性、延伸率等性能的影响。为进一步研究淀粉基阻隔膜材料奠定了坚实的理论基础。考察了不同种类淀粉酶对淀粉原料进行改性处理后,玉米淀粉分子结构、溶胶黏度和囊材力学强度的变化,最终选用异淀粉酶对其进行表面改性。进一步研究了酶用量、添加剂含量等对淀粉胶囊膜力学强度、透水性、脆碎度的影响。研究发现,经过异淀粉酶修饰后,玉米淀粉溶胶的粘度降低至3000m Pa·S左右,满足胶囊生产中蘸胶的工艺要求,有利于胶囊膜厚度的控制。加入3.0%卡拉胶、0.2%聚乙烯醇(PVA)、0.5%海藻酸钠等,不仅保证了玉米淀粉溶胶的凝胶性能,而且在吸水性能稳定的前提下,有效地增强了淀粉膜的拉伸强度和韧性。当溶胶的浓度为12%时,能够得到表面平整,厚度均一,脆碎度较低的胶囊壳及胶囊膜。通过调整异淀粉酶加入量和作用时间,可以有效地控制玉米淀粉胶囊的崩解时限,实现了对药物释放时间的控制。所制备的胶囊性能符合国家对硬质胶囊的要求,完善了纯植物医用硬胶囊的制备工艺。通过用阴离子表面活性剂十二烷基苯磺酸钠对还原氧化石墨烯进行表面改性修饰,经扫描电镜、傅里叶红外光谱、X射线衍射分析和紫外-可见光谱等表征手段的表征和检测可知：表面富含含氧基团的改性还原氧化石墨烯(r-RGO)与氧化淀粉具有较好的相容性；并且,通过对比,所得到的r-RGO复合膜材料具有较高的机械强度、阻水性和较低的光透过性,即制备的r-RGO填充淀粉基复合膜材料不仅机械强度得到了提高,而且赋予了新的阻水、遮光的功能。
[Abstract]:As one of the most common renewable natural polymer raw materials, starch has the advantages of low cost and wide range of sources. Starch resources are abundant in China. The research and innovation of starch products and related industries are related to the development of agriculture, food industry, medicine and other industries. To study the structure and properties of starch from different sources, to enlarge the type of modified starch, to improve the modification method of starch, and to develop the preparation technology and properties of its composite with different substances are the basis for the development and utilization of starch products. With the shortage of petroleum resources and the deterioration of environment, it is of great practical significance and application value to prepare starch-based composite material by using abundant, cheap and renewable starch as raw material instead of petroleum-based plastic material. Through the deepening of understanding of starch and the continuous study of additives and modification methods, it is helpful for the preparation and wide application of starch-based functional materials, which can be completely degraded, green and environmentally friendly, with low price and superior performance. In this paper, starting with the defects of starch film material's mechanical properties, the relationship between mechanical properties of starch, plasticizer, reinforcement agent and other factors is studied on the basis of the research on the relationship between mechanical properties and starch, plasticizer, reinforcing agent structure and so on. Starch-based botanical hard capsules and modified graphene-starch self-assembled composite membrane materials were prepared. By comparing the structure of different kinds of starch in the process of film-making, the properties of colloid and membrane materials, the differences between the properties of original starch and modified starch are grasped, and the strength and viscosity of various starch film materials are known concretely. In addition, the effects of such factors as sol viscosity, plasticizer content, gel and enhancer on the tensile strength, water barrier and elongation of starch-based composite membrane materials were studied. It lays a solid theoretical foundation for further study of starch-based barrier material. The changes of molecular structure, sol viscosity and mechanical strength of corn starch after modified with different kinds of amylase were investigated. Finally, isoamylase was used to modify the surface of corn starch. The effects of enzyme content and additive content on the mechanical strength, water permeability and embrittlement of starch capsule film were further studied. It was found that the viscosity of corn starch sol decreased to about 3 000 m Pa 路S after modified by isoamylase, which met the requirement of dipping gum in capsule production and was beneficial to the control of capsule film thickness. Adding 3.0% carrageenan and 0.2% polyvinyl alcohol (PVA), 0.5% sodium alginate, not only the gel properties of corn starch sol were guaranteed, but also the water absorption property was stable. The tensile strength and toughness of starch film were enhanced effectively. When the concentration of sol is 12%, the capsule shell and capsule film with flat surface, uniform thickness and low fragility can be obtained. By adjusting the amount of isoamylase and action time, the disintegration time of corn starch capsules can be effectively controlled and the drug release time can be controlled. The prepared capsules meet the national requirements for rigid capsules and improve the preparation process of pure medicinal hard capsules. Surface modification of reduced graphene oxide by anionic surfactant sodium dodecyl benzene sulfonate was carried out by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) and ultraviolet-visible spectroscopy (UV-vis) were used to characterize and test. The results showed that the modified reduced graphene oxide (r-RGO) with oxygen-rich groups on the surface had good compatibility with oxidized starch. In addition, through comparison, the r-RGO composite film material has higher mechanical strength, water resistance and lower light transmissivity, that is, the r-RGO filled starch-based composite membrane material not only has the higher mechanical strength, but also has lower light transmissivity. It also gives a new function of blocking water and shading light.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.2

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