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β-甲壳素的提取与溶解性能测试及纤维棉的纺制
【作者】 赵庆凯；
【导师】 郭宪英；
【作者基本信息】 青岛大学 ， 材料物理与化学， 2012， 硕士
【摘要】 甲壳素的储量与生物合成量非常丰富,是地球上仅次于纤维素的第二大可再生资源。由于甲壳素的分子结构特点,分子链间的氢键作用强列,使得甲壳素的溶解困难,这也是甲壳素应用过程的难题。β-甲壳素是由鱿鱼软骨中提取的不同晶型的甲壳素,其同向排列的晶型结构使其物理与化学性质比较活泼。因此,与传统α-型相比较,研究β-甲壳素更具有新的意义。本论文从β-甲壳素的制备开始,通过酸碱处理的方法制备β-甲壳素,并研究了p-甲壳素的物理与化学性质。利用乌氏粘度计测得制备的β-甲壳素的粘均分子量Mη=1.10*106,通过红外谱图(FTIR)和热重分析(TGA)等手段对β-甲壳素进行表征,并与α-甲壳素做比较。论文接下来研究β-甲壳素的溶解性能,比较三种溶剂体系：甲酸、浓碱冻融循环体系、LiCl/NMP体系的溶解情况。通过比较,LiCl/NMP体系的效果最好,最后确定了这种体系为β-甲壳素的溶解体系。本文主要研究了β-甲壳素在LiCl/NMP体系下的溶解条件与其粘度特征,通过这些测试,确定出甲壳素的最佳溶解条件在常温下溶胀约4-5h,在40℃C下搅拌溶解5h,配制约2%浓度的甲壳素的澄清透明的溶液。配制的溶液体系利用旋转流变仪,表征其流变性能。β-甲壳素的LiCl/NMP溶液在低剪切速率下为牛顿流体,n=1,随着剪切速率的升高,粘度下降,n＜1,是典型的切力变稀的流体。同时,对比试验确定其凝固浴条件,为乙醇：NaOH=9：1的凝固浴体系。对于纤维棉的纺制,采用湿法纺丝法。通过试验确定实验条件,配制约2%浓度的β-甲壳素的澄清透明的溶液,经过滤后,真空脱泡约10h,氮气加压0.2-0.6Pa,喷丝板采用1200孔,0.07mm尺寸,凝固浴采用乙醇：NaOH=9:1的凝固浴体系为第一凝固浴,乙醇为第二凝固浴。纺制出的纤维没有经过牵伸,所以不是严格意义上的纤维,可称之为纤维棉。通过红外谱图(FTIR)、扫描电镜(SEM)和热重分析(TGA)、纤维强力测试等手段研究纤维棉的形态、结构与强度等。
【Abstract】 Of reserves and biosynthesis of chitin is very abundant, is the second largest on Earth after cellulose renewable resources. Due to the characteristics of the molecular structure of chitin, the hydrogen bonds between the molecular chains strong, making difficult to dissolve chitin, which is also the problem of chitin application process,β-chitin extracted from squid cartilage in different crystal structure of chitin, with the more lively and to the ordered crystal structure to the physical and chemical properties. Therefore, compared with the traditional alpha-type of β-chitin has a new meaning.This thesis, from the preparation of β-chitin, β-chitin prepared by acid and alkali methods, and to study the physical and chemical properties of beta-chitin. Ubbelohde viscometer prepared β-chitin with a viscosity average molecular weight Mη=1.10*106, by means of infrared spectra (FTIR) and thermal gravimetric analysis (TGA) of β-chitin characterization, and a-chitin compared.The papers the next study the solubility of β-chitin, compare three solvent system:formic acid, freeze-thaw cycle system of concentrated alkali, the LiCl/the NMP system dissolved. By comparison, the effect of the LiCl/NMP system is best to finalize the system for β-chitin dissolved system. This paper studied the β-chitin dissolved in LiCl/NMP system conditions and its viscosity characteristics of these tests to determine the best dissolution conditions of chitin swelling at room temperature, about4-5h at40℃under stirring to dissolve5h, with the constraints of2%concentration of chitin to clarify a transparent solution. The preparation of the solution system using rotational rheometer to characterize their rheological properties, of LiCl/the NMP solution of β-chitin in the low shear rate Newtonian fluid, n=1, with the shear rate increased, the viscosity decreased, n<1is a typical shear-thinning fluid. Comparison test to determine the coagulation bath conditions, the coagulation bath system for ethanol:NaOH=9:1.Fiber cotton spinning, wet spinning method. Experimental conditions determined by experiments with restricting the clear and transparent solution of2%concentration of β-chitin After filtration, the vacuum deaeration of about10h, nitrogen pressure0.2-0.6Pa spinneret with1200holes,0.07mm size coagulation bath using ethanol:of NaOH=9:1coagulation bath system for the first coagulation bath, ethanol for the second coagulation bath. Spun fibers have not been drawing, so it is not the strict sense of the fibers, called fiber cotton. The infrared spectra (FTIR), scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA), the shape, structure and strength of the fiber strength testing and other means of fiber cotton.