【作者】 谭占鳌；

【导师】 ??；

【作者基本信息】 武汉理工大学 ， 应用化学， 2004， 硕士

【摘要】 再生资源高分子(Renewable Resource Polymers)来自太阳能所产生的生物量(Biomass)。它们取之不尽，用之不竭，具有可再生性，对它们的研究与利用实质就是生态资源和能量的转化、利用与研究。在石油、煤炭等化石资源日益减少和非降解合成高分子给人类生态环境造成的污染日益严重的今天，开发潜力巨大的再生资源就成为缓解压力的有效途径。本文概述了甲壳素和壳聚糖等多糖高分子新材料的研究进展、发展动态及其应用概况。 本论文的主要研究内容和结论如下： 将甲壳素进行脱乙酰基反应制得脱乙酰度为85％的壳聚糖，并用溶液纺丝法制得壳聚糖、壳聚糖／明胶复合纤维。采用红外光谱(FTIR)、X-射线衍射(XRD)、扫描电镜(SEM)和正电子湮没(PALS)表征了该纤维的结构，同时采用力学性能测试、溶菌酶降解试验及血液相容性试验研究了纤维的性能。壳聚糖与明胶在复合纤维中存在强烈的分子间相互作用。随着明胶的引入，复合纤维正电子湮没寿命谱的最长寿命组分分量逐渐降低，自由体积分数f_c值相对于纯的壳聚糖和明胶发生负偏离。壳聚糖与明胶分子间强烈的相互作用导致了复合纤维自由体积空洞尺寸的相对收缩及孔洞密度的降低，从而导致复合组分分子水平上的相容性。共混纤维的抗张强度随明胶含量的增加迅速增大，断裂伸长率却逐渐减小，其干、湿态抗张强度在明胶含量30％(wt)时最大，其值分别为1.99cN／d和0.98cN／d，比纯态壳聚糖纤维的抗张强度分别提高41％和44％。壳聚糖与明胶分子间相互作用而产生的物理交联抑制了溶菌酶对复合纤维的降解。明胶的引入，显著提高了壳聚糖纤维的血液相容性。基于以上实验事实，该复合纤维有望开发为医用缝合线等生物医用材料。 用流延法成功制得了力学性能和生物降解性能优良的壳聚糖／二氧化硅复合膜。二氧化硅的适当引入可以显著提高复合膜的干湿态强度，同时减缓其降解速度。力学研究表明，当二氧化硅含量为8％时，复合膜的干、湿态抗张强度分别为49.05MPa和27.57MPa，与纯壳聚糖膜相比(分别为38.16MPa，25.17MPa)，分别提高了28.54％和9.53％。土壤降解试验表明，壳聚糖／二氧化硅复合膜仍具有较好的生物降解性能。SEM电镜显示，当复合膜埋入土中后，其降解过程是从膜的表面开始，逐渐由表面向内部发展渗透。复合膜的生物降解性能与膜的组成有密切关系，随着二氧化硅含量的增武汉理二{_大学硕十学位论文加，其降解速率逐渐降低，这可归因于二氧化硅与壳聚糖分子间形成了氢键及交联作用，阻碍了土壤中微生物群与复合膜的降解作用。该复合膜适中的降解速率及较优的力学性能有望将该膜开发成为可降解一次性农用薄膜 在甘油塑化下，通过共混和模压成功制备了甲壳素改性大豆蛋白塑料。力学研究表明，甲壳素含量的增加提高了共混塑料的抗张强度和杨氏模量，但降低了其断裂伸长率。吸水试验显示，当甲壳素含量高于10%时，SP一C膜的吸水性明显低于不含壳聚糖的SP一CO。SEM及DSC结果表明，甲壳素分子未能与大豆蛋白分子形成强的相互作用，最终导致在共混塑料中形成了相分离结构。刚性甲壳素分子的引入，提高了共混塑料的强度和模量，同时由于甲壳素在共混塑料中形成了框架结构，限制了材料的膨胀并降低了该材料的吸水性。该共混塑料有望成为通用塑料的替代品，以缓解“白色污染”所产生的环境问题。更多还原

【Abstract】 Renewable resource polymers come from the biomass produced by solar energy. They are inexhaustible and renewable; the essential of the research and exploitation based on natural polymers actually is the research, exploitation and conversion of ecologic resource and energy. Nowadays, the petroleum and coal resources are being exhausted gradually, and the environmental pollution from the deposit of non-biodegradation synthetic polymers is becoming more and more serious. Therefore the research and development of new materials based on renewable polymer has been evaluated as an effective method to solve the existing problems. This paper reviewed the recent proceeding, current research development and application of chitin, chitosan, and their new materials. The main contents and conclusions in this paper are as follows: Chitosan with degree of deacetylation (DD) of 85% was obtained by deacetyling from chitin, and the fiber of chitosan and chitoan/gelatin were prepared by solution filature. The structure of the fibers were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD). scanning electron microscopy (SEM), and positron annihilation lifetime spectroscopy (PALS), and the property of the fibers were investigated by the tensile test, lysozyme degradation examination and blood compatibility experiment. There is strong interaction between chitason and gelatin in the blend fibers. Therefore there is a negative derivation of the fractional free volume for the blend films from the strait line between the fractional free volume of film chitosan and gelatin, indicating a constriction of free-volume hole size in the blend due to good miscibiliry of two polymers. Tensile strength (at,) of blend fibers sharply increases while breaking elongation (Sb) decreases with the content of gelatin increases. Especially when the content of gelatin reaches 30% (wt). the Ob of blend fiber in dry and wet states reaches maximum values. 1.99cN/d of Ob.ctry and 0.98cN/d of Ob.wet respectively, which are enhanced by 41% and 44% compared to the chitosan fiber. At the same time, the physical crosslink due to intermolecular strong interaction restrictes the degradation rate of lysozyme. The compatibility of the blend fibers greatly enhances with the introduction of gelatin.Base on the above facts, the composite fibers of chitosan/gelatin are to be used in medical field as seam.A series of chitosan/SiO2 composite films with good mechanical properties and biodegradation were prepared successfully by solution cast method. The results of measurements indicate that with the proper addition of SiO2 sol-gel, the dry and wet tensile strength of composite films is improved greatly. When mass percent of SiO2 reaches 8%. the best values are 49.05MPa and 27.57MPa, which increase 28.54% and 9.53% respectively compared with chitosan film(38.16MPa.25.17MPa respectively). The soil degradation test shows that chitosan/SiO2 composite films have reasonable biodegradability. SEM photos show that the biodegradation occurs from the surface of the films and gradually develops to the inside of them. The biodegradation of the composite films is closely related to the composition of the films. The rate of the biodegradation of the composite films decreases with the content of SiO2 increases. This can be attributed to the hydrogen bond and crosslink networks between the molecules of chitosan and SiO2 These composite films with good mechanical properties and biodegradation are to be used as agricultural films.A composite plastic based on soy protein isolated (SPI) and chitin (CH) was prepared with plasticization of glycerol by blending and compression-molding. Although the increase of CH content results in an enhancement of tensile strength and Young’s modulus, the incorporation of CH decreases the breaking elongation of the materials. When the CH content is higher than 10 wt%, the water absorption of SP-C sheets are obviously lower than SP-CO without CH. The added CH cannot strongly interact with SPI molecules, and更多还原