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1.
含氯磷硼酸酯聚合物的摩擦性能 总被引:2,自引:0,他引:2
合成了标题聚合物,对其进行了IR表征。利用四球试验机测定其作为润滑剂的摩擦学性能。结果表明,含磷硼酸酯的最大无卡咬负荷值大于含氯硼酸酯,而且减摩抗磨效果好;含长链疏水基团的硼酸酯的最大无卡咬负荷比短链疏水基团的高,承载能力高。EDAX能谱分析表明,其抗磨性能与摩擦表面中存在硼、氯、磷活性元素有关。 相似文献
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新型聚合硼酸酯表面活性剂PBE的合成及其性能 总被引:1,自引:0,他引:1
以偶氮二异丁腈为引发剂,用N-羟甲基丙烯酰胺、硼酸三乙酯和N,N-二羟乙基十二烷基胺直接聚合合成了新型聚合硼酸酯表面活性剂PBE。采用红外光谱、核磁共振和凝胶色谱测试技术对其进行了结构表征;考察了PBE及其硼酸酯单体MBE的抗水解性、热稳定性、乳化力等性能,并由表面张力测定研究了PBE在不同溶液pH值下的表面性质。结果表明,由直接聚合合成反应,经提纯后可得白色或淡黄色固体粉末PBE,反应收率为77.2%,产物重均分子量可达Mw=28400g/mol。PBE抗水解性能强,热分解温度可达320℃,稳定性相比单体MBE有所提高。PBE的HLB值在10~13,其对石蜡油、松节油、甲苯和石油醚的乳化力明显优于单体MBE和乳化剂Tween-85。在25℃时,随溶液pH值的增大,PBE临界胶束浓度CMC明显降低,pH值在6~7时,CMC降低幅度最大,但溶液pH对γCMC影响较小;其中pH=7时,PBE临界胶束浓度CMC达到0.12g/L,γCMC为31.2mN/m,其表面活性与常规低分子量表面活性剂的应用水平相似,而优于聚乙烯醇、聚氧化乙烯-氧化丙烯嵌段共聚物Pluronic104等常规高分子表面活性剂。 相似文献
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通过Williamson醚合成、Claisen重排及硅氢化反应得到邻羟基苯丙基硅油(Si-phenol),将其与苯酚混合,采用硼酸酯法合成有机硅改性硼酚醛树脂(SBPF).利用1H NMR和FTIR技术对其结构进行分析,采用热重分析(TGA)、剪切测试、拉伸测试以及冲击测试等手段对其耐热能和力学性能进行表征.考察了Si-phenol的含量对树脂各项性能的影响,并研究其作用机理.结果表明,合成的有机硅改性硼酚醛树脂具有良好的耐热性,适量硅氧烷链段的引入可以改善树脂的黏接性能,提高其力学强度. 相似文献
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用硫脲分子表面修饰的CdS纳米粒子的合成和表征 总被引:15,自引:0,他引:15
报道了用硫脲分子进行表面化学修饰的CdS纳米粒子的合成方法,并引入了AOT(磺基琥珀酸双-2-乙基己基酯钠盐)作为平衡反离子,进一步对CdS表面作了修饰,增加了CdS纳米粒子在有机溶剂中的稳定性和可分散性。我们还探讨了温度、浓度、pH等因素对合成的影响,并通过TEM、XRD、FT-IR等手段对产物结构进行了表征。所得微粒粒径为5 nm左右,呈球形,硫脲分子与CdS纳米粒子富Cd2+表面通过形成Cd-S配位键而修饰在粒子表面。这种表面修饰的CdS纳米粒子将在非线性光学及自组装方面具有优 相似文献
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制备了一系列羧基支化改性双子表面活性剂,其利用马来酸酐将2个疏水性基团和2个亲水性基团通过弱酯键连接基团连接在一起,以反丁烯二酸为羧化试剂在过氧化自由基的引发下进行羧化接枝反应接入了阴离子亲水基团。用红外光谱和核磁共振表征了合成物的分子结构。测定了合成产物的表面张力、胶团形貌、疏水性能、泡沫性能、润湿性能、乳化性能和分散性能。结果显示所合成的双子表面活性具有优异的表面性能。 相似文献
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Wang Yonggang Li Na Liu Ping Dai Bin Han Sheng 《Research on Chemical Intermediates》2020,46(2):1283-1295
Research on Chemical Intermediates - The effect of amine on the tribological properties and hydrolytic stability of borate ester additives was examined by adding different kinds and quantities of... 相似文献
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Yujiang Fan Masami Kobayashi Hideo Kise 《Journal of polymer science. Part A, Polymer chemistry》2001,39(9):1318-1328
Novel polyesteramides were synthesized from p‐nitrophenyl esters of sebacic or adipic acids and diamines containing α‐amino acid ester groups. The optimal polymerization condition was 60 °C in N,N‐dimethylformamide. The structures of these polymers were confirmed by IR and NMR. The number‐average molecular weights of these polyesteramides ranged from 2280 to 23,600 (except for the polymers containing glycine residues), depending on the nature of the amino acid used. The biodegradability of the polyesteramides was investigated by in vitro hydrolysis with proteases and a lipase as catalysts in borate buffer solutions. The results indicated that the polymers containing L ‐phenylalanine were hydrolyzed most effectively by α‐chymotrypsin, subtilisin Carlsberg, and subtilisin BPN′. The polyesteramides containing other amino acid residues also underwent hydrolysis to different extents, reflecting the substrate specificity of the proteases. Lipase had almost no effect on the hydrolytic degradation of these polyesteramides. The polymers containing glycine residues were hardly decomposed by any of the enzymes used. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1318–1328, 2001 相似文献
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Phenylsilatrane analogues containing reactive amino, bromo, boronic ester, and alkynyl functional groups for coupling reactions have been prepared. Pinacol boronic ester and ethynyl analogues were synthesized from 4-bromophenylsilatrane by palladium catalyzed reactions. The silatrane functional group was shown to be stable during the palladium catalysis procedures and silica-gel purification, making the molecules amenable to further synthetic manipulation. The described phenylsilatranes are useful building blocks for forming more complex organosilatrane species. 相似文献
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Huricha Baigude Kaname Katsuraya Kousaku Okuyama Yoshihide Yachi Shoma Sato Toshiyuki Uryu 《Journal of polymer science. Part A, Polymer chemistry》2002,40(21):3622-3633
A reactive three‐layered dendrimer containing carboxyl groups was synthesized by the coupling of dicarboxylic acid and a highly reactive, two‐layered glycopeptide dendrimer. Lactose, maltose, or maltotriose was reacted with the poly(lysine) dendrimer in its third and fourth generations by reductive amination and afforded two‐layered glycolysine dendrimers. The reaction was conducted in a borate buffer (pH 9.0). 1H NMR, 13C NMR, and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry analyses were applied for the determination of the structures of the products. When an excess amount of the oligosaccharide and a long reaction time were used, the degree of substitution increased to 1.5–2.0 against an amino group. For the preparation of highly reactive, multilayered dendrimers for an antigen carrier, C6 hydroxy groups of the oligosaccharides were selectively esterified by adipic acid and suberic acid to give 6‐O‐adipoyl oligosaccharide–poly(lysine) dendrimers and 6‐O‐suberoyl oligosaccharide–poly(lysine) dendrimers. The reactivity of these multilayered dendrimers was examined by a model reaction with phenylalanine ethyl ester. The dendrimer showed high reactivity, providing phenylalanine ethyl ester–dicarboxylate oligosaccharide–poly(lysine) dendrimers with a considerably high proportion of phenylalanine residues. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3622–3633, 2002 相似文献
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Carsten Dingels Dr. Frederik Wurm Dr. Manfred Wagner Prof. Dr. Harm‐Anton Klok Prof. Dr. Holger Frey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(52):16828-16835
The covalent attachment of poly(ethylene glycol) (PEG) to therapeutically active proteins (PEGylation) has become an important method to deal with the pharmacological difficulties of these polypeptides, such as short body‐residence times and immunogenicity. However, the derivatives of PEG used for PEGylation lack further functional groups that would allow the addition of targeting or labeling moieties. Squaric acid diethyl ester was used for the chemoselective single‐step activation of poly(ethylene glycol)s into the respective ester amides. The resultant selective protein‐reactive poly(ethylene glycol)s were investigated with respect to their selectivity towards amino acid residues in bovine serum albumin (as a model protein). The presented procedure relies on a robust two‐step protocol and was found to be selective towards lysine residues; the activated polyethers are efficient and stoichiometric PEGylation agents with a remarkable hydrolytic stability over a period of several days. By adjusting the pD value of the conjugation mixture, the chemoselectivity of the activated PEGs towards the α‐ and ε‐amino groups of lysine methyl ester was effectively changed. 相似文献
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The double Suzuki cross‐coupling reaction has successfully been applied for the synthesis of 5,5′‐(5‐butoxy‐1,3‐phenylene)bis(2‐chloropyrimidine) with two reactive chloro groups and an alkoxy side chain starting from 2‐chloropyrimidin‐5‐ylboronic acid and 1,3‐dibromo‐5‐butoxybenzene. The reactivity of this dielectrophile was tested by reaction with aniline and phenol, a nitrogen and oxygen nucleophile, respectively. The new dielectrophile would further provide an ideal platform for the construction of large hetero‐atom bridged macrocycles for desired properties and functions in supramolecular and material chemistry. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Metal ion detection using a fluorescent dye containing reactive ester groups allows discrimination on the basis of the hydrolytic reactivities of metal ions, which display the same qualitative fluorescence response on binding only. 相似文献
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Li Qun Xu Bin Zhang Yu Chen Koon‐Gee Neoh En‐Tang Kang Guo Dong Fu 《Macromolecular rapid communications》2013,34(3):234-238
Graphene oxide (GO) nanosheets can be functionalized with reactive pentafluorophenyl ester via esterification of the carboxylic groups. The resulting reactive GO nanosheets provide a versatile platform for grafting of amino‐containing polymers or biomolecules via ester–amine coupling. Coupling of poly[(9,9‐dioctylfluorene)‐alt‐(4‐amino‐phenylcarbazole)] (PFCz‐NH2), amino‐terminated hyperbranched polyglycerol (HPG‐NH2), and lysozyme (Lyz) was illustrated. The Al/GO‐g‐PFCz/ITO sandwich thin‐film device exhibits bistable electrical switching and rewritable memory effects. The GO‐g‐Lyz nanohybrids exhibit high bactericidal efficacy against S. aureus and E. coli, while the GO‐g‐HPG nanohybrids exhibit reduced cytotoxicity toward 3T3 fibroblasts. 相似文献
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Leticia Larios‐López Rosa Julia Rodríguez‐González Bertrand Donnio Daniel Guillon 《Liquid crystals》2013,40(5):549-554
A series of penta(p‐phenylene)s modified with short and long alkoxy groups was synthesized via palladium complex‐catalysed cross‐coupling reactions. Molecules substituted with butoxy groups in the central ring showed a nematic phase characterized by a schlieren optical texture, whereas those molecules lacking lateral groups, or substituted with shorter than butoxy groups, did not exhibit liquid crystallinity. Also, it was determined that both the mesophase stability and the clearing point were strongly dependent on the length of the terminal chains. Finally, optical studies of these compounds indicated that the observed light absorption/emission characteristics are independent of the chain lengths. 相似文献
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Boric acid forms meta-stable complexes with biomolecules like amino and hydroxy acids and stable complexes with the diol group
containing carbohydrates, vitamins, and nucleotides, yielding mono-chelate (1: 1 complex) or bis-chelate (1: 2 complex) structures
with negatively charged tetrahedral borate anions. Here we report water-soluble, bio-available mixed-ligand boron adducts
for potential nutritional and/or pharmaceutical applications. The complexes were prepared by complete esterification of boric
acid with a number of acyclic- and cyclic hydroxy-functionalized biomolecules employing sodium as the counter ion. Structural
and thermal properties of the complexes were investigated using chemical analysis, 11B NMR, FTIR, and TGA-DTA techniques. Complexes containing salicylic acid as one of the ligands displayed higher thermal and
hydrolytic stabilities. 相似文献