【作者】 易英；

【导师】 汪玉庭；

【作者基本信息】 武汉大学 ， 环境科学， 2005， 博士

【摘要】 在环境污染日益严重的今天,合成高分子材料给人类日常生活和工业带来许多方便和巨大利益。然而,其生物难降解性对人类生存环境造成了巨大的危害。壳聚糖以其良好的环境相容性、可再生性、资源丰富以及价廉易得等优点而受到人们的关注。对壳聚糖进行化学改性赋予其新的功能且扩大其应用范围已经成为研究热点。本论文概述了壳聚糖及衍生物的的研究进展、发展动态及其应用状况,并采用改性及衍生化等方法扩大壳聚糖功能材料的应用范围。 主要内容和结论如下: （1）利用4-甲酰基苯并15-冠-5接枝交联壳聚糖对钯有着较高的吸附选择性,运用壳聚糖冠醚衍生物作为催化剂对苯乙酮进行不对称催化氢化的研究,结果表明:在交联壳聚糖接枝4-甲酰基苯并15-冠-5吸附氯化钯后,配位键主要是在氮原子与钯原子之间,同时在冠醚与钯之间形成了较弱的配位。实验结果证明新催化剂4-甲酰基苯并15-冠-5接枝交联壳聚糖钯能够在常温常压下对苯乙酮进行不对称加氢催化。（R）-1-苯基乙醇-1光学产量对配合物中钯的含量、溶剂以及温度非常敏感。在温度为30℃,以乙醇为溶剂,每克催化剂中含钯1.43mmol,苯乙酮浓度为0.02g·mL^-1时（R）-1-苯基乙醇-1的光学产率可达97.1%。壳聚糖生物高分子与钯配合物作为催化剂很容易从反应体系中被分离出来,重复使用四次光学产率几乎没有变化。本研究将促进交联壳聚糖冠醚吸附金属应用于不对称加氢催化的研究。 （2）通过壳聚糖与环氧氯丙烷与4,4’-二甲酰基二苯并18-冠-6反应,制得了壳聚糖衍生物西佛碱型二苯并18-冠-6交联壳聚糖（CCTS-1）和仲胺型二苯并18-冠-6交联壳聚糖（CCTS-2）。研究了对银的吸附性能,结果表明银离子浓度为0.5 mmol·L^-1时,CCTS-2吸附银离子最佳条件是pH为6.0,且在1小时内吸附速率非常快。在加入壳聚糖衍生物6小时后被吸附的金属离子量保持稳定,表明吸附达到平衡并且形成了稳定的银离子络合物。在1小时后CCTS-2对银离子的吸附率为96%。实验表明,含有0.00355 mmol Ag⁺的CCTS-2—Ag⁺对Staph. Aureus, E. coli和Pseudomonas aerugJnona细菌的抑制区域的直径分别为11毫米、10毫米和7.5毫米,而在相同条件下交联壳聚糖吸附银离子更多还原

【Abstract】 With increasing environmental pollution, the wide use of synthetic polymeric materials gives advantages of great convenience and benefits. However, their difficult biodegradability causes great destruction to our survival environment. Chitosan’s merits of good enviromental compatibility, renewability, rich resources, and low cost make it under observation. The paper describes the development of chitosan and its derivatives, researching state, and application. The paper also provides methods of modification or derivation for magnifing the applied scope of functional chitosan material.The main contents and conclusions are described as follows: （1） The crosslinked chitosan grafted by 4’ -formal benzo-15-crown-5 obtained crosslinked chitosan with 4’-formal benzo-15-crown-5 （CCTS-N=CH-B-15-C-5） . Then it was loaded with palldium chloride to gain the heterogeneous catalyst, which was easily isolated from the reaction system. The influences of the Pd content of the catalyst, solvent, and temperature on asymmetric hydrogenation of α -phenylethanone have been studied. The catalyst has been found to catalyze the hydrogenation of α -phenylethanone into the chiral alcohol, α -phenyl ethanol under the mild condition. The optical yield of （R）-l-phenylethanol could be obtained in 97.1 % on the following conditions: temperature, 30°C; solvent, ethanol; Pd content, 1.43 mmol/g; substrate concentration, 0.02 g·mL^-1 thanks to cooperative effect of crown ether and chitosan polymer. The stability of this catalyst was also studied at the same time. This chiral natural crosslinked chitosan-palladium complex catalyst could be reused without appreciable change in optical catalytic activity, which will be useful for designing crosslinked-chitosan-based adsorption for metal ions for asymmetric hydrogenation.（2）New di-Schiff base type crown ethers crosslinked chitosan （CCTS-1） was synthesized by the reaction of 4, 4’-diformyldibenzo-18-c-6 crown ether with crosslinked chitosan. New di-secondary amine type crown ethers crosslinked chitosan（CCTS-2） was prepared by the reaction between CCTS-1 and sodium borohydride. Their structures were confirmed by Fourier transform infrared spectral analysis, X-ray powder diffraction analysis and elemental analysis. The adsorption rates by CCTS-2 for Ag+ for 1 h were 96% at pH 6.0, Ag+ initial concentration 0.5 mmol’L"1. The complexes of CCTS （Ohga, Kurauchi & Yanase, 1987）, CCTS-2 and silver ion against three bacteria were studied. The bacteriostasis zone diameters of the complex of CCTS-2 and Ag+ （CCTS-2—Ag+） containing 0.00355 mmol Ag+ against Staph. Aureus, E.coli and Pseudomonas aeruginona are 11, 10 and 7.5 millimeter accordingly while those of the complex of CCTS and Ag+ （CCTS— Ag+） at the same condition are 11, 10 and 6.0 millimeter accordingly. This research will be useful for designing crosslinked-chitosan-based adsorption for preconcentration of Ag+ for medical bacteriostasis.（3） A new adsorbent for bilirubin, chitosan immobilized with j5-cyclodextrins （CTC）, has been prepared by the reaction of chitosan and allyl-substituted j8-cyclodextrins. Its structure has been confirmed by infrared spectra analysis and X-ray diffraction analysis. The experimental results showed this adsorbent for bilirubin has a higher capacity 6.33 mg’g"1 than CTS at initial concentration 14.5 mg* L1 at 20 °C. It was mainly derived from the torus of j?-cyclodextrins on CTC and hydrogen bond between CTC and bilirubin. The adsorption for BR of CTC was accorded with Freundlich isothermal equation. This new adsorbent might be applied as biomedical adsorbents in the removal of bilirubin in medical administration.（4）We first prepared the intermediate hydroxylpropyl chloride of chitosan（CSl）. By the reaction of hydroxylpropyl chloride of chitosan and /?-cyclodextrins, a novel chitosan grafted withj#-cyclodextrins （CC） has been gained. Their structures were characterized by IR and X-ray diffraction, which were in accordance with the designed ones. The apparent grafted amount of j#-cyclodextrins was 25.48 //mol^g"1 by UV-9100 ultraviolet-visible spectrophotometer. The influences of initial concentration, adsorption time, pH, and ion strength on adsorption capacity for salicyclic acid were studied. This kind of modified resin has a higher adsorption capacity for salicyclic acid than chitosan itself （CTS）. The maximium adsorption forsalicyclic acid on CC was 55.2% while on CTS was 49.1%. The chitosan grafted with jtf-cyclodextrins （CC） needed about 180 minute to get adsorption equilibrium.（5）The novel chitosan microspheres grafted with jS-cyclodextrins （CMGC） were prepared by means of the reaction of chitosan microspheres which were prepared successfully by phase-inversion method, and mono-（6-p-tosyl）- jS-cyclodextrins （）8-CD-OTs-6) gained by the reaction of /Moluenesulfonyl chloride （TsCl） and j3-cyclodextrin （ji-CD）. Their structures were proved by Fourier transform infrared spectral analysis （FT-IR）, X-ray powder diffraction analysis, and 13Carbon Nuclear Magnetic Resonnance （13C NMR）; the configuration of CMGC was characterized by scanning electron micrograph （SEM） and transmittance electron micrograph （TEM）. The inclusion complex of CMGC with iodine was prepared and its inclusion ability was studied. The experimental results showed that some iodine was included with CMGC and formed a stable inclusion. The stable complex of CMGC and iodine （CMGC-I） shows good antibacterial effect.（6）The new diethylene triamine derivative of chitosan was synthesized by the reaction of diethylene triamine and chitosan activated with epoxy. The product contained amino functional groups, secondary amine and polar hydroxyl groups in its skeleton. Its structure was proved by elemental analysis, infraed spectra analysis, and X-ray diffraction analysis. It was in accordance with expected one. The static adsorption properties for Pd2+> Ag\ Ni2\ Cu2\ Co2+andCd2+ were studied. The experimental results demonstrated the new diethylene triamine derivative of chitosan has higher adsorption capacity for metal ions. The adsorption capacities for Ag+ and Pd2+ were 1.29 and 1.15 mmol’g \ respectively. In the coexistence of Cu2+and Ni2+, it had a high adsorption selectivity for Ag+ ion. The selectivity coefficients were K Ag+/CB2+ =11.73 for CTSN and KAg+/c?2+=3.2 for CCTS. The adsorption capacity for Ag+ was greatly influenced by pH and ion strength.The main innovative points are as follows:（l）The crosslinked chitosan with 4’ -formal benzo-15-crown-5 loaded withpalldium chloride was first applied in asymmetric hydrogenation. The new catalyst has been found to selectively catalyze the hydrogenation of a -phenylethanone intothe chiral alcohol;a -phenyl ethanol under the mild condition. XPS analysis has been used to characterize the mechanism of 4’-formal benzo-15-crown-5 loaded with palldium chloride and the influences on catalytic hydrogenation were discussed.（2）New di-secondary amine type crown ethers crosslinked chitosan adsorbed silver ion was first used in antibacteria. The antibaterial activity of it was studied;which provided new idea for magnifing the antibacterial activity and application ofchitosan.（3）Considering good inclusive behavour of jS-cyclodextrins and biocompatibility of chitosan;new routes and application about the reaction of /?-cyclodextrins and chitosan are as follows:?The novel chitosan microspheres grafted with jS-cyclodextrins adsorbediodine to obtain the adsorbent which was applied in antibacterial tests. It had thesame antibacterial activity as pure iodion.However;it was more stable than pureiodine.?By means of the new way of the reaction of chitosan and allyl-substitutedj3-cyclodextrins;biocompatible chitosan immobilized with ft — cyclodextrinswas obtained. In the scope of low concentration;its adsorption on bilirubin wasstudied.（3）By the new reaction of hydroxylpropyl chloride of chitosan and fi-cyclodextrins;a novel chitosan grafted with P -cyclodextrins has been gained.It was first applied in the adsorption of salicyclic acid and the influences onadsorbing salicyclic acid were also studied.（4）The new derivative method for chitosan was searched to prepare new diethylene triamine derivative of chitosan. The adsorption on heavy metal ions was discussed.更多还原