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醋酸乙烯酯—二乙烯苯大孔共聚物的合成及其结构性能的研究 总被引:3,自引:2,他引:1
制备了以醋酸乙烯酯为单体,以二乙烯苯为交联剂的共聚物小球,分别测定了它们的交联度,致孔剂的性质和用量,共聚时间等诸因素对共聚物的比表面积,孔容,平均孔径,表观密度和骨架密度的影响。 相似文献
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本文在研究醛类化合物与尿素反应的基础上,确定含有α-羰醛基的化合物在pH7.4,37℃下对尿素有较高的反应活性。将α-羰醛基引入到苯乙烯-二乙烯苯共聚物骨架上,合成出带有α-羰醛基的树脂。实验结果表明,含α-羰醛功能基的树脂在pH7.4,37℃条件下与目前临床使用的氧化淀粉相比,具有更大的吸附潜力。本文还研究了吸附条件对该树脂吸附性能的影响。 相似文献
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聚合物固载化聚乙二醇季胺盐型相转移催化剂的结构与催化活性 总被引:3,自引:0,他引:3
The gelatinous and macroporous phase transfer catalysts with multiple active centers were synthesized by means of quarterisation of PEG tertiary amine and chloromethylated St DVB copolymer. They were examined as phase transfer catalysts in the reaction of n C 8H 17 Br with solid NaI. The experimental results showed that the reaction rate was first order with respect to the concentration of n C 8H 17 Br. The effects of catalyst structure on the catalytic activity were also investigated. The observed reaction rate constant ( k obsd ) increased as the degree of cross linking of polymer decreased. Macroporous catalysts showed a higher activity (2~2 5 times) than that of microporous catalysts with the same degree of cross linking of polymer, particle size and amount of supported PEG. Molecular weight of PEG also showed much influence on k obsd . As molecular weight of PEG rose properly, the catalysts showed a higher activity. The results were discussed from the aspect of triphase catalysis reaction mechanism. 相似文献
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微波作用下的多肽固相缩合反应及动力学研究 总被引:2,自引:0,他引:2
分别在微波作用以及传统加热两种方式下, 研究了Fmoc-Val-OH与NH2-Tyr(t-Bu)-Wang树脂的固相缩合反应及其动力学. 测定了温度变化对反应速率的影响, 并获得了两种方式下的缩合反应的宏观动力学参数: 300 W微波作用下表观缩合反应级数为2.3, 活化能为104.7 kJ/mol; 传统方法中表观反应级数为2.9, 活化能为142.4 kJ/mol. 微波作用将常规条件下的连接率由68%提高到95%, 而所需时间降为常规条件的1/14. 相似文献
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高分子固-固相转变材料是近年来新兴的课题,其主要优点是体积变化小,发生相转变时不出现液态,可以减少对容器的要求,甚至不需要容器即可把相变材料作为结构材料,可简化工艺和降低成本,我们相继合成了系列聚乙二醇/聚乙烯醇高分子固-固相变材料,由于形成交联网络结构,难溶于一般有机溶剂。 相似文献
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SBS与甲基丙烯酸丁酯本体接枝反应的研究 总被引:1,自引:0,他引:1
本文研究了以过氧化苯甲酰(BPO)为引发剂,甲基丙烯酸丁酯(BMA)既作溶剂又作为单体与苯乙烯-丁二烯嵌段共聚物(SBS)进行接枝共聚反应。用红外光谱、核磁共振谱及透射电镜表征了接枝共聚物(SBS-g-BMA)的组成及结构,讨论了时间、温度及SBS和BPO的用量对接枝的影响。 相似文献
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聚乙二醇-聚苯乙烯接枝共聚物的合成及其接肽反应性能 总被引:1,自引:0,他引:1
本文应用环氧乙烷在羟乙基树脂上的开环聚合方法,合成了凝胶和大孔型聚乙二醇-聚苯乙烯接枝共聚物(简称PEG树脂)。对不同类型载体的接肽反应动力学性能研究表明,在PEG树脂载体上的反应速度是在氯甲基化树脂上的三倍,与在溶液中进行的接肽反应速率相当。此外,还对载体性能与树脂交联度、骨架结构之间的关系进行了初步探索。 相似文献
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聚苯乙烯树脂固载聚乙二醇及吡啶翁盐的合成及其活性评价 总被引:3,自引:0,他引:3
以氯甲基化聚苯乙烯为原料,先后接枝聚乙二醇及吡啶,合成了双中心固载相转移催化剂-交联聚苯乙烯固载聚乙二醇400及吡啶翁盐,并对氯甲基化聚苯乙烯树脂、聚苯乙烯固载聚乙二醇树脂、聚苯乙烯固载吡啶翁盐树脂及双中心树脂进行了红外光谱测试和分析。通过醋酸钾与溴苄的反应,对各催化剂进行了活性评价。发现固载双中心相转移催化剂的活性明显高于各单向中心固载相转移催化剂。 相似文献
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The polyethylene glycol resin (PEG-Resin) which possesses hydrophilic properties was prepared by grafting the polyethylene glycol onto the chloromethylated copolymer of styrene and divinylbenzene in the presence of concentrated sodium hydroxide solution. The proceeding of the graft reaction was identified by IR spectrum analysis. There factors which affected the grafting reactions were investigated. By using the PEG-Resin polymer support, we compared the reactions for the syntheses of a tetra-peptide and a penta-peptide with the Merrifield solid peptide synthesis. We also measured the reaction kinetics of these reactions. The experimental results showed that by employing the PEG-Resin, the reaction rates and condensation yields of these peptide syntheses were improved. 相似文献
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本文报道聚乙二醇(PEG)及其单醚类化合物在咪唑N-烷基化反应中的催化效应,它是以组成聚乙二醇的(CH_2CH_2O)单元中的氧同Im~-Na~+形成离子对参与反应的.催化剂活性与分子量关系不大,主要取决于分子链中有效的(CH_2CH_2O)单元个数,并以不少于5的单元个数组成配合基元通过界面传递阴离子.在一定的催化剂浓度下,遵循假一级反应动力学关系.由此求得的不同碳链(C_4~C_(16))烷基溴和咪唑发生N-烷基化反应的速度常数,显示碳链的空间结构对反应有明显的影响.咪唑和正-丁基溴发生N-正丁基化反应的活化能为12.4±0.5kcal/mol,还求取了该反应的活化参数△S、△H、△G,并与使用季铵盐和冠醚类化合物作相转移催化剂(PTC)的反应结果进行了对比. 相似文献
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氨基酸衍生物的反应、合成和生物活性研究 总被引:2,自引:0,他引:2
讨论了我们小组近年来以氨基酸衍生物为主线,在代谢型谷氨酸受体及蛋白激酶C有选择性的调节剂的发现和合成,在发展新反应以及天然产物合成方面所取得的一些结果。 相似文献
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The kinetics of the oxtraction of U(IV) chloride in the TOPO-HCl system has been studied using the single drop technique, The effects of the concentrations of U(IV, TOPO and HCl on the extraction rate for U(IV) have been examined. The extraction rate measured were found to be of first order with respect to (U(IV)) and (TOPO) (0). Moreover, the rate varied with (HCl)^3^/^2 between 2-7M hydrochloric acid. The extraction rate equation can be written as R=K(U(IV))(TOPO)(0) The rate constant K was evaluated to be 3.7X10^-^5 at 3M HCl and 15`C. The extraction rate was increased with increasing temperature. The apparent activation energy was found to be 10.8 kcal/mol between 15 to 45`C. It is suggested that the rate-controlling step may be the chemical reaction of UCl4 with TOPO at the interface and the formation of the interfacial complex UCL4.TOPO. 相似文献
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