共查询到17条相似文献,搜索用时 93 毫秒
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研究了以丙烯酸甲酯、己二胺、对苯二酚为原料,采用发散法合成新型端胺基聚酰胺-胺树枝状大分子时,反应条件——温度、反应时间、催化剂对合成产物的结构的影响。利用该树枝状大分子的活性点分布均匀的特点,通过设计和控制树枝状大分子模板剂来控制纳米粒子材料的形状。 相似文献
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TRIS封端树枝状大分子PAMAM的合成 总被引:1,自引:0,他引:1
采用发散法合成了以乙二胺为核的树枝状大分子聚酰胺-胺(PAMAM),以端基为酯基的半代PAMAM和三羟甲基氨基甲烷(TRIS)为原料,无水碳酸钾为催化剂,分别以二甲基亚砜和甲醇为溶剂,合成了端基被修饰的水溶性大分子PAMAM-OH和PAMAM-K,产率分别为80.3%和74.1%.采用红外光谱对产品结构进行了表征,同时对其水溶性和表面活性进行了初步的研究,结果表明:PAMAM被水溶性基团修饰后,失去了表面活性,却增强了水溶性. 相似文献
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聚酰胺-胺树枝状高分子及其研究进展 总被引:4,自引:0,他引:4
介绍聚酰胺胺树枝状高分子的结构和性能,聚酰胺胺的特殊结构决定了其独特的物化性质。同时,对其合成方法、及其经改性后的树枝状高分子在生物医药、表面活性剂、催化剂、污水处理和膜材料等方面的应用研究进展进行了综述。 相似文献
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聚酰胺-胺(PAMAM)是一种新型树枝状大分子,其改性和应用是目前研究的热点。PAMAM已在多个领域显示出良好的应用前景。本文综述了PAMAM在生物医药、表i面活性剂、催化剂、光电材料、分子自组装、纳米材料、水处理等方面所取得的成果。 相似文献
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氨为核树状大分子聚酰胺-胺的制备与破乳性能 总被引:4,自引:0,他引:4
采用发散法以氨为核、甲醇为溶剂,交替与丙烯酸甲酯和乙二胺反应,合成了0.5-3.0代的树枝状大分子聚酰胺-胺,采用端基滴定分析对分子的结构进行了表征,并研究了它们对模拟原油乳液的破乳性能。结果表明:它们与以乙二胺为核心的树枝状大分子聚酰胺-胺所表现出来的趋势完全一致。 相似文献
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通过固相合成的方法将聚酰胺-胺树状大分子PAMAM担载于大孔硅胶上,并对其外围分别用对羟基苯甲醛、2,4-二羟基苯甲醛和邻羟基苯甲醛进行修饰,再与SnCl2.2H2O反应形成三类共计9种不同代数树状高分子锡配合物。将该类配合物用作质量分数30%双氧水氧化酮的Baeyer-Villiger(B-V)反应的催化剂,考察其催化活性,结果表明,在该类配合物作用下,2-金刚烷酮、环戊酮、环己酮、4-甲基环己酮、4-叔丁基环己酮、3-甲基-2-戊酮和4-甲基-2-戊酮都可以发生B-V氧化反应而转化为相应的酯和内酯,底物的转化率(75%~99%)和产物选择性(95%~100%)都较高。比较了不同载体(氯球、纤维素、壳聚糖、硅胶)、不同配体的金属锡配合物对B-V催氧化反应的催化效果,研究发现,载体、配体和金属担载量对配合物的催化活性均有不同程度的影响。其中,硅胶为最好的载体,而邻羟基苯甲醛为最好的配体。 相似文献
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M Venu Madhav C
B Ching 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2001,76(9):941-948
The hydrolysis of racemic methyl ibuprofen ester in the presence of lipase from Candida rugosa was investigated in shake flasks. Experiments were performed to study the effect of temperature, pH and shaking speed on the reaction rate. Different hydrophobic co‐solvents were screened for the highest reaction rate and the presence of enzyme inhibition by substrate and products was examined. A kinetic expression was then proposed to describe the reaction. Kinetic parameters were determined for the optimum operating conditions and the proposed model was verified with the experimental results. Next, this reaction was scaled up to a fed batch stirred tank reactor. Batch reactor and fed batch reactor configurations were compared for better conversions. The effects of aqueous phase hold‐up, substrate concentration and feed flow rate on the conversion of the reaction were also studied. Higher conversions were obtained in a fed batch reactor when compared with the batch reactor. In the fed batch reactor, increased conversions were observed with lower feed flowrates and high aqueous phase hold‐up. © 2001 Society of Chemical Industry 相似文献
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Ding Zhang Jianrong Xia Hanyu Xue Yuchi Zhang Qi Lin 《Polymer Engineering and Science》2020,60(6):1177-1185
In this study, polyamidoamine (PAMAM) was added to raw lacquer in different proportions, and the curing process and properties of lacquer film were investigated by using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). To investigate the cross-linking state between PAMAM and urushiol, NMR was used in this study. The experiments revealed that the comprehensive mechanical properties of modified-film, especially the impact strength, were significantly improved. In addition, the touch-free drying time of lacquer film decreased, and its alkali resistance was improved due to the cross-linking of PAMAM and urushiol molecules. 相似文献
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Changes in the physical structure of Alberta hvCb coal upon partial solubilization in tetralin, Athabasca bitumen and the oil fraction from the bitumen were determined from gas adsorption measurements, mercury porosimetry and petrographic examination. It was shown that solubilization of the coal generated new micropores, while the macropore structure was degraded. Resistance to extraction due to pore structure is considered to be probably of minor importance. The experimental results suggest that low molecular weight material in the coal was preferentially liquefied. 相似文献