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1.
采用强碱溶液对壳聚糖的羟基进行O-羧甲基化,再用叶酸偶联0.羧甲基壳聚糖。然后用红外光谱扫描法、紫外分光光度法和电位滴定法分别对产物进行了表征,并计算了叶酸对O-羧甲基壳聚糖的修饰量。结果显示羧甲基壳聚糖的取代度为38.28%,且O-羧甲基壳聚糖能够较好地溶于中性和碱性水溶液中。所测叶酸对O-羧甲基壳聚糖的修饰量为17.8μg·mg^-1。  相似文献   

2.
6—O—羧甲基壳聚糖的乳化性能与结构的关系   总被引:3,自引:0,他引:3  
研究了甲壳素羧甲基化反应条件对产物结构的影响,讨论了6-O-羧甲基壳聚糖的乳化性能与结构的关系,结果表明,产物取代度在0.7 ̄0.9之间,-NH2含量〉64%,粘度〉0.14Pa·s,产物具有良好的乳化性和水溶性,并通过响应中面分析(RSA)优化了改性条件,最佳反应条件是:甲壳素用40%NaOH溶液浸4h,在碱与氯乙酸重比为1.2:1和温度40℃条件下反应2h 50℃  相似文献   

3.
研究了在水媒介中,利用微波加热使壳聚糖发生羧甲基改性反应。探讨了碱化时间、微波加热时间、投料比等工艺条件对壳聚糖羧甲基化程度及产物收率的影响,并对产物进行了红外光谱分析、取代度测定、粘度分析。确定最佳工艺条件。壳聚糖:氢氧化钠:氯乙酸=1:15:12,碱化时间=2h,微波加热时间=25min,制得羧甲基壳聚糖取代度和收率分别为0.71和83%。  相似文献   

4.
水溶性甲壳素衍生物的制备及应用   总被引:13,自引:0,他引:13  
本文介绍了水溶性甲壳素衍生物的分子结构,阐述了O-羧甲基甲壳质、O-羧甲基壳聚糖及N,O-羧甲基壳聚糖的制备方法及它们的用途。  相似文献   

5.
羧甲基壳聚糖的制备与性能研究   总被引:1,自引:0,他引:1  
以壳聚糖为原料制备了羧甲基壳聚糖,考察了NaOH用量、一氯乙酸用量、反应时间和反应温度对羧甲基壳聚糖取代度的影响,得出羧甲基化的最佳条件为:壳聚糖/一氯乙酸/氢氧化钠(m/m)=1:3.2:4,反应时间为3h,反应温度为60℃,制得产物的水溶性有较大提高,并利用红外光谱对产物结构进行了表征。  相似文献   

6.
通过接枝反应合成了具有两亲性的羧甲基壳聚糖-油酸聚合物,并测定了临界胶束浓度(CMC),评价其形成胶束的能力。首先对壳聚糖进行羧甲基化修饰,酸碱滴定法测定取代度,并以取代度为指标,正交实验法确定合成羧甲基壳聚糖过程中不同条件对取代度的影响,根据正交实验结果制备了3种不同取代度的羧甲基壳聚糖,分别与油酸进行接枝反应,合成了3批羧甲基壳聚糖-油酸聚合物,荧光光度法分别测定CMC值为0.013 8、0.039 0和0.039 0 mg/mL,结果表明羧甲基壳聚糖-油酸具有形成胶束结构的能力。  相似文献   

7.
壳聚糖及其衍生物的制备和保湿吸湿性能评价   总被引:6,自引:0,他引:6  
简要介绍了壳聚糖及其衍生物的制备方法和物化性质。以甘油、山梨醇和透明质酸为参照物,在一定相对湿度下考察了壳聚糖、羧甲基壳聚糖、N—羧丁基壳聚糖等几种保湿剂的保湿吸湿性能。结果显示,羧甲基壳聚糖和N—羧丁基壳聚糖的保湿吸湿性能最优,完全可以替代透明质酸,作为多种化妆品的保湿剂。  相似文献   

8.
N,O—羧基壳聚糖制备及其保温性能研究   总被引:1,自引:0,他引:1  
阐述了制备N,O-羧甲基壳聚糖的工艺路线和方法,并测定其保温、吸湿性能。结果表明:制备N,O-羧甲基壳聚糖最佳工艺条件为NaOH:ClCH2COOH=0.9:1,异丙醇:壳聚糖=12:1(质量比);反应温度65℃,反应时间2.5h,得到的产品在保湿、吸湿方面明显优于甘油。  相似文献   

9.
通过羧烷基化对壳聚糖进行改性,发现当壳聚糖与氯乙酸、壳聚糖与氢氧化钾的质量比分别为1:4.26及2:2.3时,45℃下反应4.5h,可得到O-羧甲基壳聚糖,产率为97.1%,对产品进行红外光谱表征.在此基础上研究了制备的O-羧甲基壳聚糖对Ni2+的吸附性,探讨溶液pH、Ni2+初始浓度和取代度等因素对其吸附性的影响.结果表明,最佳吸附条件是溶液pH为8.0、Ni2+初始浓度为33.2778 mg·mL-1、O-羧甲基壳聚糖取代度为0.712、平衡吸附时间为6 h.对O-羧甲基壳聚糖进行脱附研究,结果显示H2SO4是一种很好的脱附剂,能在0.5h内将吸附在O-羧甲基壳聚糖上的Ni2+脱去90%以上,重现性好.  相似文献   

10.
羧甲基壳聚糖合成条件的优化及产物结构表征   总被引:4,自引:0,他引:4  
通过异相法的方法合成了絮凝剂羧甲基壳聚糖.根据羧甲基壳聚糖对废水中Cd^2 的去除率,利用四因素三水平正交实验优化了羧甲基壳聚糖的合成条件。正交实验的结果表明优化反应条件为:反应时间7h,反应温度为50℃,氯乙酸对壳聚糖的质量比为1.25,氢氧化钠对壳聚糖的质量比为1.0。在此优化条件下得到的羧甲基壳聚糖产品对Cd^2 的最大去除率可达99.7%,用IR和^1H NMR对相应的产品进行了结构表征,结果表明羧甲基化反应发生在C2位上NH2处的程度高于C6位的OH。  相似文献   

11.
利用O-羧甲基壳聚糖(O-CMC)的表面多种官能团(如-NH_2,-OH,-COOH等)与胆酸(CA)进行化学修饰得到两亲性共聚物,再以反溶剂法将Fe_3O_4和阿霉素(DOX)包埋在两亲性共聚物疏水的核中,制备两亲性的磁性壳聚糖载药纳米粒子,并对磁性载药纳米粒子的形貌、粒径大小、磁性、药物控释等进行了研究。结果表明:磁性壳聚糖纳米粒子有较高的药物包埋效率(92.3%),与自由阿霉素相比,磁性复合物具有明显的缓释作用和pH响应性;同时,有较好的超顺磁性。这些说明制备的疏水修饰磁性壳聚糖载药纳米粒子具有双重响应性,有望作为药物输送载体对肿瘤进行实时跟踪、诊断和治疗。  相似文献   

12.
以水溶性O-羧甲基壳聚糖(O-CMC)与聚琥珀酰亚胺(PSI)为原料,合成了聚天冬氨酸接枝共聚物阻垢剂PASP/O-CMC。用FTIR与1HNMR对阻垢剂的结构进行了表征,用静态阻垢法考察了PASP/O-CMC和聚天冬氨酸(PASP)的阻垢性能。结果表明:当阻垢剂质量浓度为100 mg/L、温度为80℃、时间为16 h、pH=10时,PASP/O-CMC对BaSO_4的阻垢率达到93.6%,而PASP对BaSO_4的阻垢率只有78.4%。通过SEM、XRD和电导率法分析了阻垢剂的阻垢机理,结果表明:阻垢剂对BaSO_4的作用主要包括晶格畸变作用、吸附分散作用和络合作用。  相似文献   

13.
The effects of O-carboxymethylation modification on the coacervation of chitosan with gum arabic (GA) were investigated. O-carboxymethylated chitosan (O-CMC) carried less net positive charge in acidic solutions and its optimum pH and biopolymer ratio for coacervation with GA were lower than those of native chitosan. O-carboxymethylation modification decreased the optimum coacervation temperature from 45 to 25°C and greatly increased the sensitivity to ionic strength. Meanwhile, insoluble O-CMC–GA coacervates were formed in relative lower critical total biopolymer concentration than chitosan–GA coacervates. It was concluded that the O-carboxymethylation modification markedly influenced the electrostatic interaction of chitosan with GA.  相似文献   

14.
O-carboxymethyl chitosan (O-CMC)–gum arabic (GA) coacervates separated in different acidities were crosslinked by genipin and subjected to FTIR analysis, viscoelasticity measurement, DSC characterization, pH response evaluation, and in vitro BSA release profiling to explore the influence of coacervation acidity on genipin crosslinking and intestine-targeted delivery potency of the coacervates. Genipin crosslinking greatly improved the stability of the coacervates against various simulated gastrointestinal fluids and the coacervation acidity exerted different effects on the pH response of coacervates and BSA-loaded microcapsules. It was concluded that genipin-crosslinked O-CMC–GA coacervates could be used to deliver hydrophobic compounds to the intestine.  相似文献   

15.
Chitosan, which is derived from a deacetylation reaction of chitin, has attractive antimicrobial activity. However, chitosan applications as a biocide are only effective in acidic medium due to its low solubility in neutral and basic conditions. Also, the positive charges carried by the protonated amine groups of chitosan (in acidic conditions) that are the driving force for its solubilization are also associated with its antimicrobial activity. Therefore, chemical modifications of chitosan are required to enhance its solubility and broaden the spectrum of its applications, including as biocide. Quaternization on the nitrogen atom of chitosan is the most used route to render water-soluble chitosan-derivatives, especially at physiological pH conditions. Recent reports in the literature demonstrate that such chitosan-derivatives present excellent antimicrobial activity due to permanent positive charge on nitrogen atoms side-bonded to the polymer backbone. This review presents some relevant work regarding the use of quaternized chitosan-derivatives obtained by different synthetic paths in applications as antimicrobial agents.  相似文献   

16.
Liping Sun  Lihong Fan  Jianhong Yang 《Polymer》2006,47(6):1796-1804
Quaternized carboxymethyl chitosan (QCMC) was prepared from which carboxymethyl chitosan (CMC) was prepared from chitosan first, then N-quaternary ammonium group was introduced by the reaction of CMC with 2, 3-epoxypropyl trimethylammonium. The structures of the derivatives were characterized by FT-IR, XRD, 13C NMR, 1H NMR and gel permeation chromatography. In vitro antimicrobial activities of QCMC were evaluated against Escherichia coli, which is a Gram-negative bacterium, and Staphylococcus aureus, which is a Gram-positive bacterium. In compared with carboxymethyl chitosan (CMC) and quarternary chitosan (QC) of the same degree of substitusion (DS), we found that QCMC has stronger antimicrobial activity. Then we went deep into study of the relationship between their structure and antimicrobial activity, found that the DS of CMC do little effect to their antimicrobial activity, but as the increase of their DS of quaternization or the decrease of their molecular weight, the antimicrobial activity of QCMC become stronger. QCMC was complexed with calcium hydroxide as pulp-cap. Animal experiment results indicated that QCMC can strongly induce reparative dentine formation and showed a better ability in dentin inducing compared with calcium hydroxide.  相似文献   

17.
Chitosan, a biocompatible, biodegradable, nontoxic polymer, is prepared from chitin, which is the second most naturally occurring biopolymer after cellulose. Schiff base of chitosan, sorbyl chitosan, and p‐aminobenzoyl chitosan were synthesized working under high‐intensity ultrasound and their antimicrobial properties were analyzed against Escherichia coli, Staphylococcus aureus, and Aspergillus niger. The structures of the derivatives were characterized by FTIR spectroscopy and elemental analysis. The results of antimicrobial activities indicated that the antimicrobial activities of the derivatives increased with increasing the concentration. The antibacterial activity of schiff base of chitosan against E. coli was stronger, while acylated chitosan had better inhiting effect on S. aureus than others. It was also found that the antifungal activities of the derivatives were stronger than that of chitosan, and schiff base of chitosan was obviously superior to acylated chitosan. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

18.
The objective of the present study performed was to develop and characterize of silver (Ag)-doped titanium dioxide (TiO2) naoparticles (NPs) encapsulated in chitosan–polyvinyl alcohol (PVA) film for synergistic antimicrobial activity. The acidic solution of chitosan with PVA was used for the reduction of silver ions into silver NPs using their functional groups such as hydroxyl, carboxyl, and amino groups. The chitosan–PVA silver nanoparticle films showed significant antimicrobial and antifungal activity against Staphylococcus aureus, Candida albicans, and Pseudomonas aeruginosa. Therefore, the present study is an alternative for conventional treatment as antimicrobial film showed synergistic, noninvasive, and economic effects.  相似文献   

19.
壳聚糖抗菌活性研究进展   总被引:1,自引:0,他引:1  
壳聚糖具有无毒、良好的生物相容性、生物可降解性、广谱抗菌性等优良性能,作为新型抗菌剂越来越受学者的青睐。本文主要综述了21世纪以来影响壳聚糖抗菌性能的因素、壳聚糖的抗菌机理以及壳聚糖衍生物抗菌性能等方面的内容。  相似文献   

20.
近年来甲壳胺纤维在抗菌纺织品、医用敷料等产品中得到广泛的应用。这些产品利用了甲壳胺纤维的广谱抗菌性能,以及它的吸湿性和促进伤口愈合的性能。由于甲壳胺的分子结构中有反应活性很高的氨基,通过对氨基的化学改性可以得到具有特殊功能的改性甲壳胺纤维。介绍了近年来开发的几种典型的功能性改性甲壳胺纤维。  相似文献   

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