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101.
CuCl/沸石双功能羰基化催化剂催化合成叔碳酸 总被引:1,自引:0,他引:1
Bifunctional carbonylation catalysts were prepared by introducing both of acidic and metallic sites into zeolites, such as β, M and Y, by which tertiary butyl acid was synthesized under mild reaction conditions. The effects of reaction temperature and the copper amount as well as the acid strength on the catalytic activity were investigated. The results show that when the content of cuprous for β, M and Y are 2 35%, 2 48% and 7 13% respectively, the carbonylation activity of the related sample is the greatest. In the reaction temperature range, lower temperature is favorable for yielding acid and higher temperature is favorable for yielding ester. The catalytic activity increases with the increase of the acid strength. The in situ FT IR study shows that Cu(Ⅰ) is the metallic active site. 相似文献
102.
103.
104.
十二烷基磺酸铁催化合成丙酸正丁酯 总被引:4,自引:1,他引:3
以十二烷基磺酸铁催化合成了丙酸正丁酯。实验结果表明最佳反应条件为:丙酸100mmol,n(丙酸):n(正丁醇)=1.0:1.2,十二烷基磺酸铁0.8g(约1.0mmol),带水剂环己烷6mL,回流分水60min,酯化率94.6%。催化剂重复使用5次仍保持较高活性。 相似文献
105.
Chuanbing Huang Arumugam Vignesh Chantsalnyam Bariashir Qaiser Mahmood Yanping Ma Yang Sun Wen‐Hua Sun 《Journal of polymer science. Part A, Polymer chemistry》2019,57(10):1049-1058
A new family of t‐butyl substituted chromium(III) chloride complexes ( Cr1 – Cr6 ), bearing 2‐(1‐(2,6‐dibenzhydryl‐4‐t‐butylphenylimino)ethyl)‐6‐(1‐(arylimino)ethyl)pyridine (aryl = 2,6‐Me2C6H3 Cr1 , 2,6‐Et2C6H3 Cr2 , 2,6‐i‐Pr2C6H3 Cr3 , 2,4,6‐Me3C6H2 Cr4 and 2,6‐Et2‐4‐MeC6H2 Cr5 ) or 2,6‐bis(1‐(2,6‐dibenzhydryl‐4‐t‐butylphenylimino)ethyl)pyridine ( Cr6 ), has been synthesized by the reaction of CrCl3·6H2O in good yield with the corresponding ligands ( L1 – L6 ), respectively. The molecular structures of Cr2 and Cr6 were characterized by X‐ray diffraction highlighted a distorted octahedral geometry with the coordinated N,N,N ligand and three bonded chlorides around the metal center. On activation with modified methylaluminoxane or triisobutyl aluminum, most of the chromium precatalysts exhibit good activities toward ethylene polymerization and produce linear polyethylenes with high‐molecular weight. In addition, an in‐depth catalytic evaluation of Cr2 was conducted to investigate how cocatalyst type and amount, reaction temperature, and run time affect the catalytic activities and polymer properties. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 1049–1058 相似文献
106.
Yuko Ikeda Kazutoshi Kodama Kanji Kajiwara Shinzo Kohjiya 《Journal of Polymer Science.Polymer Physics》1995,33(3):387-394
Poly(ethylene oxide)-grafted butyl rubbers (IIR-g-PEOs), which were synthesized from potassium salt of polyethylene glycol monomethyl ether (PEGM) and chlorinated butyl rubber, were found to behave like thermoplastic elastomers. The poly(ethylene oxide) (PEO) content of these amphiphilic polymers was ca. 10 wt %, and their PEO lengths were 750, 2000, and 5000, respectively. The grafted segments of PEO in butyl rubber (IIR) aggregated to form the PEO domains in IIR matrix. At constant PEO content, the longer the PEO segment length, the larger the size and the crystallinity of PEO domains became. This PEO domain worked as a cross-linking site and a reinforcing filler. The degree of swelling in water of IIR-g-PEO film that was prepared from PEGM-5000 was largest, but its emulsification ability was smallest among them. © 1995 John Wiley & Sons, Inc. 相似文献
107.
Gas transport of helium, hydrogen, oxygen, nitrogen, methane, and carbon dioxide gases in a series of polyarylates based on isophthalic acid has been examined. These polyarylates were prepared from bisphenol A, hexafluorobisphenol A, phenolphthalein, and fluorene bisphenol monomers to study the effects of varying the bisphenol connector group size and shape. Substitution of a tertiary butyl group at position five on the isophthalate ring increases polymer permeability. The incorporation of a large, bulky connector group increases gas permeability and maintains permselectivity while the substitution of t-butyl groups increases gas permeability by two- to fourfold but lowers permselectivity. Most of the increases in permeability can be related to increases in the diffusion coefficients of all the gases. All the polyarylates have high glass transition temperatures and may be suitable for high temperature gas separation applications. ©1995 John Wiley & Sons, Inc. 相似文献
108.
Osman Yilmaz Ali Usanmaz Kemal Alyürük 《Journal of polymer science. Part A, Polymer chemistry》1993,31(13):3205-3211
n-Butyl isocyanate (nBIC) was polymerized in bulk by the Pruitt–Baggett adduct (PBA) at ?23, 0.0, and 25.0°C. Polymerization was accompanied by trimerization to the cyclicisocyanurates at all temperatures. Spectroscopic evidences supported the nylon-1 structure for both trimer and polymer. The polymer/trimer ratio and the molecular weight of produced polymers were found to increase with decreasing temperature. The Pruitt–Baggett catalyst (PBC), which is the reaction product of (PBA + H2O) system, also polymerized nBIC, but with a relatively slower rate. In aromatic and etheric solutions, nBIC was only trimerized by PBA. Copolymerization of nBIC with propylene oxide by PBA and PBC failed. Some selected monoisocyanates were also polymerized by PBA. © 1993 John Wiley & Sons, Inc. 相似文献
109.
The effect of the nitrogen purge, monomer purification, type of agitation, and presence of costabilizer on the particle size distribution (PSD) was investigated in the dispersion po-lymerization of styrene in ethanol and in the dispersion copolymerization of styrene and butyl acrylate in a water–ethanol mixture. Purging with nitrogen and, to a lesser extent, monomer purification, were of paramount importance to achieve monodispersity. The type of agitation had a week effect on the PSD, whereas the presence of costabilizer had no effect on the PSD. © 1995 John Wiley & Sons, Inc. 相似文献
110.
Recent advances and applications in 1,2,4,5-tetrazine chemistry 总被引:2,自引:0,他引:2
Nurullah Saracoglu Author Vitae 《Tetrahedron》2007,63(20):4199-4236