羽毛角蛋白提取及其与纤维素复合材料的制备与性能研究

发布时间：2018-02-14 10:12

本文关键词： 废弃羽毛角蛋白纤维素干燥条件复合材料　出处：《江南大学》2017年硕士论文　论文类型：学位论文

【摘要】：近些年,由于资源短缺和环境污染的双重压力,越来越多的科研人员开始关注天然可再生资源的开发和利用。我国每年产生大量的废弃羽毛,其主要成分为角蛋白。纤维素是自然界贮备最多的天然高分子,如果科学的开发羽毛角蛋白和纤维素并制造出可降解的生物质材料,便可有效解决资源短缺和环境污染的问题。为此本论文进行了以下几个方面的研究:首先,利用半胱氨酸作为还原剂从废弃鸡毛中提取出角蛋白,碳酸钠-碳酸氢钠缓冲溶液再溶解角蛋白制成均匀的混合溶液,通过延流成型法和湿法纺丝制备纯角蛋白膜和纤维。采用扫描电子显微镜(SEM)、傅立叶变换红外光谱(FT-IR)、X射线衍射(XRD)和热重分析(TGA)来表征原鸡毛、角蛋白粉末、角蛋白膜和纤维的结构和性能。对比原鸡毛,再生角蛋白材料保留了原鸡毛的化学结构和热稳定性。它们的相对结晶度由于成型工艺的不同而有略微差别,结晶度的不同也导致了这四种材料的吸湿性的差异。机械性能显示,角蛋白膜材料的拉伸强度可达3.5MPa,在生物医学领域具有潜在的应用价值。然而,角蛋白纤维的拉伸性能并不是很理想,比如强度只有0.5cN/dtex,在之后的研究中会进一步解决这一问题,使得新纤维应用于纺织和材料科学中去。其次,采用室温晾干、冷冻干燥、真空干燥和烘箱干燥四种方式对再生纤维素膜进行干燥,并通过SEM、FT-IR、XRD、热重分析、纳米压痕仪和万能试验机研究纤维素膜在不同干燥条件下结构及性能的差异。实验结果表明,真空干燥和烘箱干燥所得纤维素膜的表面光滑硬挺,但微观表面有裂纹产生,冷冻干燥膜的微观结构相对疏松,但没有裂纹,这使得冷冻干燥膜在机械性能方面优于其他干燥方式得到的纤维素膜。微观力学方面,以真空干燥膜和烘箱干燥膜的弹性模量和硬度最为优良,这主要是因为在这两种干燥方式中较高的温度使水分快速挥发,进而纤维素大分子相互靠拢形成了致密的微观结构。最后,将角蛋白和纤维素在离子液体中共混制备出角蛋白/纤维素复合膜和纤维,通过SEM、FT-IR、XRD、TGA和万能试验机来表征不同成分比例的复合膜材料。利用膜材料中两种聚合物复合的最佳比例制备复合纤维,并对纤维的形貌和力学性能进行了初步探索。利用离子液体可以成功地制备出性能良好的角蛋白/纤维素的复合材料。实验结果表明,当离子液体:纤维素:角蛋白为95:5:3时,复合膜的结晶度最高,从而拉伸断裂强度最高,可达到112.53MPa。纯纤维素膜的拉伸断裂伸长率可达到17.07%,一旦加入角蛋白便会急剧下降。加入角蛋白后的复合膜的热稳定性比纯纤维素和纯角蛋白有明显提高,这也是复合材料所具有的特性。角蛋白/纤维素复合纤维细度均匀并且力学性能良好,对于复合纤维其他性能方面还需要进一步的研究。
[Abstract]:In recent years, due to the double pressure of resource shortage and environmental pollution, more and more researchers begin to pay attention to the development and utilization of natural renewable resources. Cellulose is the most abundant natural polymer in nature. If we scientifically develop feather keratin and cellulose and produce biodegradable biomass materials, Therefore, the following aspects were studied in this paper: firstly, keratin was extracted from waste chicken hair by using cysteine as reducing agent. Sodium carbonate and sodium bicarbonate buffer solution dissolved keratin into a homogeneous mixture solution, Pure keratin films and fibers were prepared by casting and wet spinning. The raw chicken hair and keratin powder were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The structure and properties of keratin film and fiber. Compared with the original chicken hair, the regenerated keratin material retains the chemical structure and thermal stability of the original chicken hair. Their relative crystallinity varies slightly due to the different molding process. The difference of crystallinity also leads to the different hygroscopicity of these four materials. The mechanical properties show that the tensile strength of keratin membrane material can reach 3.5 MPA, which has potential application value in biomedical field. The tensile properties of keratin fibers are not very good. For example, the strength of keratin fibers is only 0.5 CN / dtex. this problem will be further solved in later studies, so that the new fibers can be used in textile and materials science. Secondly, they can be dried at room temperature and freeze-dried. The regenerated cellulose membrane was dried by vacuum drying and oven drying. The difference of structure and properties of cellulose membrane under different drying conditions was studied by means of SEMFT-IRXRD, thermogravimetric analysis, nano-indentation instrument and universal testing machine. The surface of cellulose film obtained by vacuum drying and oven drying is smooth and stiff, but cracks occur on the micro surface. The microstructure of freeze-drying film is relatively loose, but there is no crack. The mechanical properties of freeze-drying film are superior to those obtained by other drying methods. In micromechanics, the modulus of elasticity and hardness of vacuum drying film and oven drying film are the best. This is mainly because the higher temperature in these two drying methods makes the moisture volatilize rapidly, and then the cellulose macromolecules converge to form a compact microstructure. Keratin / cellulose composite membranes and fibers were prepared by blending keratin and cellulose in ionic liquids. The composite membrane materials with different composition ratios were characterized by SEMT-IR TGA and universal testing machine. The composite fibers were prepared by the optimum proportion of two kinds of polymers in the membrane materials. The morphology and mechanical properties of the fiber were preliminarily explored. A good keratin / cellulose composite was successfully prepared by using ionic liquids. The experimental results showed that when the ionic liquid: cellulose: keratin was 95: 5: 3, The composite film has the highest crystallinity and thus the highest tensile fracture strength. The elongation at tensile break of the pure cellulose membrane can reach 17.07, and once keratin is added, the thermal stability of the composite membrane can be decreased sharply, and the thermal stability of the composite membrane after adding keratin is obviously higher than that of pure cellulose and pure keratin. This is also the property of the composite material. The keratin / cellulose composite fiber has uniform fineness and good mechanical properties, and further research is needed on the other properties of the composite fiber.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS102.1

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