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1.
高分子化叔丁基氢醌的抗氧化活性研究   总被引:2,自引:0,他引:2  
通过叔丁基氢醌(TBHQ)与苯乙烯-马来酸酐交替共聚物的酯化反应制备了高分子化的叔丁基氢醌(PTBHQ)。经测定,高分子化的叔丁基氢醌的抗氧化活性、热稳定性和持久作用能力均较高分子化前增强  相似文献   

2.
众所周知,受阻胺光稳定剂对聚烯烃有良好的光稳定效率,已引起世界的注意。然而,小分子量的受阻胺易于挥发,从而影响它的效率发挥[1,2],为了克服这个缺点,使小分子受阻胺的高分子化是近年来受阻胺光稳定剂发展的方向,本文主要是研究三种商品化高分子受阻胺光稳定剂对聚丙烯的稳定化作用及其效率和机理。  相似文献   

3.
首次研究了聚乙烯醇缩对甲酰基偶氮胂(PV-pFASA)的合成、纯化及其鉴定方法.并初步探讨了在光度分析和非有机溶剂革取分离方面的应用.结果表明,小分子显色剂高分子化后.其分析性能有了明显改善,特别是显色灵敏度和萃取率均有不同程度的提高.  相似文献   

4.
首次报道了聚乙烯醇缩对甲酰基偶氮氯膦(简称:PV·CPpF)的合成、纯化及其鉴定方法,并初步探讨了在光度分析和非有机溶剂萃取分离方面的应用。结果表明,小分子显色剂高分子化后,其分析性能有了明显改善,特别是显色灵敏度和萃取率均有不同程度的提高。  相似文献   

5.
高分子化铁系烯烃聚合催化剂的合成及乙烯聚合   总被引:1,自引:0,他引:1  
刘长坤  金国新 《化学学报》2002,60(1):157-161
合成了含烯丙基不对称型的“茂后”催化剂[ArN=C(Me)][Ar'N=C(Me)]C~5H~3NFeCl~2[Ar=2,6-(i-Pr)~2C~6H~3,Ar'=4-烯丙基-2,6-(i-Pr)~2C~6H~3],通过IR,^1HNMR,EI-MS,EA对化合物进行表征。利用这个催化剂上的烯烃基团在自由基引发下与苯乙烯共聚,制备出高分子化的“茂后”催化剂。研究了高分子化前后催化剂催化乙烯聚合行为,高分子化的催化剂在常压13℃下催化乙烯聚合时,活性最高达到2.5×10^6gPE/molFe.h,高于未高分子化之前催化剂的活性。证明了高分子化是“茂后”催化剂理想的固载化方式。  相似文献   

6.
研究了聚乙烯醇缩对甲酰基苯偶氮变色酸(Polyvinylalcoholcondensedpoformylphenylazochromotropicacid,称PVA·FPAC)的结构与性能。结果表明,小分子试剂甲酰基苯偶氮变色酸(FPAC)高分子化后,性能有了较大的改善;表现为不同聚合度和羟基取代度(聚乙烯醇主链上羟基被取代的程度)的高分子显色剂其性能有较显著的差异;就聚乙烯醇缩对甲酰基苯偶氮变色酸而言,同一聚合度的试剂,羟基取代度越大,溶解性越好,显色反应的灵敏度越高,但对非有机溶剂液-固萃取影响不大;对不同聚合度的试剂,聚合度高的,显色灵敏度和萃取率均有明显提高。  相似文献   

7.
<正> 以2,2,6,6-四甲基哌啶为母体的衍生物作为受阻胺光稳定剂,其效率约为镍-螯合物光稳定剂的2—6倍,已引起人们的注意,但是小分子受阻胺易于挥发,从而使其光稳定作用较差。为了克服上述缺点,使受阻胺稳定剂高分子化是近年来展的趋势,本文合成了含有“丙烯”单元的高分子受阻胺光稳定剂——丙烯-马来酸哌啶酯共聚物,力求改进它与丙烯的相容性,提高光稳定效率,本文还对共聚物进行表征。  相似文献   

8.
小分子药物高分子化能延长药效,减小副作用,是改进现有药物的重要方法之一。目前研究的高分子药物大致有两类:(1)高分子本身有药效;(2)高分子本身无药效,但可释放出小分子药物。例如,Vogl等合成的5-乙烯基水杨酸甲酯聚合物本身有抗紫外辐射功能,李福绵等合成的聚甲基丙烯酸-β-(乙酰水杨酰氧)乙酯等本身虽不是药,但可释放出阿斯匹林。我们希望合成出兼有以上两类特点的高分子药物,为此合成了几种常见药物的高分子衍生物:聚甲基丙烯酸水杨酸酯(PSAMA),聚甲基丙烯酸对乙酰胺基苯酯(PAPMA),聚甲基丙烯酸磺胺嘧啶酰胺(PSDMA)和聚甲基丙烯酸乳酸酯(PLAMA)。  相似文献   

9.
羟丙基甲基纤维素;包覆;无机有机复合粒子;接枝共聚合;聚氯乙烯;超细SiO2表面高分子化及其在PVC复合材料中的应用  相似文献   

10.
在合成含有8-羟基喹啉(8HOQ)配位基单体的基础上,将其与甲基丙烯酸甲酯(MMA)共聚得到含有8-羟基喹啉侧基的聚甲基丙烯酸甲酯(PMMA8q),实现了8-羟基喹啉的高分子化;通过PMMA8q和小分子协同配体与稀土离子Eu(Ⅲ)的配位反应,制备了两个稀土高分子发光配合物:Eu(PMMA8q)(8HOQ)2(H2O)3和Eu(PMMA8q)2(TTA)(H2O)3(TTA:噻吩甲酰三氟丙酮)。利用元素分析、红外光谱方法对各阶段产物进行了表征,用荧光光谱研究了两个稀土高分子配合物的荧光特性及发光机理。  相似文献   

11.
<正> 阿斯匹林是近年来发现具有抗血小板凝聚效应的普通药物。在酯基上含有阿斯匹林基团的亲水性丙烯酸酯聚合物的水解研究表明,这些聚合物有可能作为控制释放阿斯匹林的生物相容性释放体系。本文合成了甲基丙烯酸β-(乙酰水扬酰氧)乙酯(HEMAASA)与甲基丙烯酸(MA)的共聚物,观察其水解行为,以期寻找能够进一步控制释放阿  相似文献   

12.
The liquid chromatography of aspirin, salicylic acid and acetic acid using cation exchange resins with aqueous alcohol and water as eluent was described. The results indicated that acetic acid could be separated from aspirin and salicylic acid by hydrogen form cation exchange resin with 25% ethanol or water as eluent. The possibility of using this method to determine the degree of hydrolysis of aspirin was discussed.  相似文献   

13.
The copolymers of 1-(acetylsalicylyloxy)ethyl methacrylate (HEMA-ASA) with methacrylicacid (MA) have been prepared and their hydrolysis in dioxane-H_2.O either in acdic or alkaline medium,at 60℃or 37℃have been investigated. It is found that the chief product of hydrolysis is alwaysaspirin with minor amount of salicylic acid. Due to its neighbouring group effect, the hydrolysisrate of (HEMA-ASA)-MA copolymer markedly depends on its composition and the pH value ofhydrolysis medium, i.e. the hydrolysis rate increases with increasing mole fraction of MA in the copoly-mer and pH value of hydrolysis medium.  相似文献   

14.
Geometric structures and excited-state proton dislocation of size-selected salicylic acid clusters (salicylic acid and 5-methoxysalicylic acid) with water were studied by using laser spectroscopic techniques. Fluorescence excitation, dispersed fluorescence, and infrared (IR) spectra of those clusters in supersonic jets were examined for both the electronic ground (S0) and first excited (S1) states. The geometric structures of the clusters were determined on the basis of the IR spectra of the OH stretch region with the help of quantum chemical calculations. The hydroxyl group of the water moiety in the clusters forms a ring involving the carboxylic group of the salicylic acid moiety. The IR spectra in S0 show that the intramolecular hydrogen bond in the salicylic acid moiety is still held upon cluster formation, but the phenolic OH stretch band intensity is remarkably weaken in the clusters. The IR spectra in the S1 state and dispersed fluorescence spectra indicated that the intramolecular excited state proton dislocation is hardly affected by the microsolvation with water, in contrast with the strong suppression of the dislocation in the self-solvation.  相似文献   

15.
《Analytical letters》2012,45(6):629-640
Abstract

A method has been developed to simultaneously determine aspirin, salicylic acid, salicyluric acid, and gentisic acid concentrations in human plasma and urine. An extraction and dry-down step prepare the sample for resolution by reverse-phase high pressure liquid chromatography. The column effluent is monitored by both ultraviolet absorbance and fluorescence to optimize sensitivity and specificity for the compounds of interest.  相似文献   

16.
通过Mannich反应,由水杨酸、甲醛和甲胺合成了一种在主链上含有水杨酸基和叔胺基的新型聚电解质SFMA。用SFMA作为聚合物催化剂催化P-硝基苯酚乙酸酯(PNPA)的水解反应。动力学研究结果表明,在较高的pH值下,SFMA比水杨酸及其与甲醛的缩聚物具有较高的加速作用。缩聚物主链上的胺基能与水杨酸基的羟基发生协同作用。对缩聚物的组成及其在水溶液中的构象对催化活性的影响也进行了研究。  相似文献   

17.
A novel direct high-performance liquid chromatographic (HPLC) assay for the simultaneous determination of three salicylate glucuronide conjugates and other salicylate metabolites in human urine has been developed. Salicylate glucuronide conjugates were purified by HPLC from the urine of a volunteer after oral administration of aspirin and identified by selective hydrolysis with beta-glucuronidase and with sodium hydroxide. This method gave high reproducibility with coefficients of variation less than 10%. The total urinary recovery of salicylic acid after a single 1.2-g dose of soluble aspirin was greater than 90%. This assay has been successfully used to re-evaluate the capacity-limited pharmacokinetics of salicylic acid in humans.  相似文献   

18.
《Analytical letters》2012,45(12):903-912
Abstract

The method for the analysis of aspirin and salicylic acid in human plasma has been updated to include advances in column technology, extraction procedures and absorbance detection. Aspirin and salicylic acid are extracted from acidified plasma into an organic solvent system containing internal standard. Following controlled evaporation under partial vacuum of the organic extract, the dried down-residue is reconstituted with mobile phase. Chromatography is ion suppression reverse phase on a 5 μm O.D.S. column with detection by absorbance at 237 nm and optional fluorescence. Concentration of aspirin as low as 0.20 μg/ml and salicyclic acid as low as 0.50 μg/ml can be quantitated.  相似文献   

19.
建立测定阿司匹林合成过程中水杨酸、阿司匹林含量和转化率的分析模型。采用紫外多波长扫描乙醇溶液中阿司匹林和水杨酸的紫外光谱,建立水杨酸和阿司匹林紫外光谱的向量长度与其质量浓度的标准曲线,通过斜投影算法分离出待测样本中阿司匹林和水杨酸的紫外光谱。计算光谱向量长度,代入标准曲线得到待测样本中阿司匹林和水杨酸的含量。实验结果表明,水杨酸、阿司匹林的质量浓度与其紫外光谱的向量长度呈良好的线性关系,线性范围分别为2.00~40.00,10.00~200.00μg/m L。水杨酸和阿司匹林测定结果的相对标准偏差为0.16%~2.19%(n=5),加标回收率在93.3%~106.9%之间。该方法快速简便、准确可靠,可满足阿司匹林和水杨酸的同时测定及反应过程中水杨酸转化率监测要求。  相似文献   

20.
阿司匹林合成过程中所采集的阿司匹林、水杨酸和乙酸酐的拉曼光谱存在交迭现象,很难从光谱数据中分离各组分含量。根据反应体系的组成和浓度配制样本溶液并采集拉曼光谱,运用多种方法对光谱进行预处理结合偏最小二乘法(PLS)对混合体系中阿司匹林、乙酸酐和水杨酸3组分浓度和光谱矩阵建立回归模型,对回归结果进行比较,根据交互验证均方根误差RMSECV,预测相关系数帮,预测均方根误差RMSEP。结果表明预处理方案可以有效降低基线漂移对预测精度的影响,根据Q值检验法和严检验法确定经矢量归一+Savitzky-Golay五点二次平滑一阶卷积求导+均值中心化对拉曼光谱预处理,PLS主成分选4,交互验证选用“逐一法”可时阿司匹林反应体系3组分进行同时测定,此训练集为阿司匹林合成体系的拉曼光谱在线监测提供了良好的数据支持。  相似文献   

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