ChemInform Abstract: HYDRATION TRIMERIZATION OF ACETYLENE IN SUPERBASIC MEDIA. I. SYNTHESIS OF 2-VINYLOXY-1,3-BUTADIENE AND IDENTIFICATION OF SECONDARY REACTION PRODUCTS

1983 ◽  
Vol 14 (8) ◽  
Author(s):  
O. A. TARASOVA ◽  
S. V. AMOSOVA ◽  
B. A. TROFIMOV
Keyword(s):  
Secondary Reaction ◽  
Reaction Products ◽  
Superbasic Media

Sulfur Linkage in Vulcanized Rubber. Reaction of Methyl Iodide with Sulfur Compounds

1949 ◽  
Vol 22 (1) ◽  
pp. 1-7
Author(s):  
M. L. Selker
Keyword(s):  
Methyl Iodide ◽  
Room Temperature ◽  
Sulfur Compounds ◽  
Point Of View ◽  
Secondary Reaction ◽  
Reaction Products ◽  
Sulfide Sulfur ◽  
Vulcanized Rubber ◽  
Allyl Sulfide

Abstract The work described here is an extension of the study of the reaction of methyl iodide with sulfur compounds originally begun with the purpose of using such data in determining the sulfur linkage in vulcanized rubber. A previous paper dealt with the reactions of methyl iodide with propanethiol, propyl sulfide, propyl disulfide, allyl sulfide, and thiophene. This article adds to the list, n-butyl methallyl sulfide, allyl disulfide, allyl tetrasulfide, n-propyl tetrasulfide, and trithiane. The removal of combined sulfur from vulcanized rubber as trimethylsulfonium iodide on treatment with methyl iodide at room temperature was persuasive evidence of the presence of sulfide sulfur linked to allylic type residues. The evidence offered, however, did not constitute exclusive proof because it was not known whether still other types of sulfur linkage would also yield trimethylsulfonium iodide. To shed more light on this question, the sulfur linkages most likely to occur in vulcanizates—the allyl-alkyl monosulfide, diallyl and dialkyl di- and polysulfide—were investigated. The trithiane reaction is of interest mostly from the point of view of the reaction of overcured stocks or secondary reaction products stemming from the original polysulfides. The reactions were carried out using the method described in a previous paper.

RADIATION CHEMISTRY OF CYCLOHEXANE: IV. PRIMARY PRODUCT YIELDS IN THE IRRADIATION OF CYCLOHEXANE

1961 ◽  
Vol 39 (12) ◽  
pp. 2381-2388 ◽  
Author(s):  
P. J. Dyne ◽  
J. A. Stone
Keyword(s):  
Radiation Chemistry ◽  
Secondary Reaction ◽  
Reaction Products ◽  
Primary Reaction ◽  
Product Yields ◽  
Primary Products ◽  
High Irradiation

The radiolysis of cyclohexane has been studied at low total doses and initial G values have been determined. Ninety-nine per cent of the evolved hydrogen has been accounted for in hydrogen-deficient products. Cyclohexene, bicyclohexyl, and cyclohexyl-hexene-1 have been identified as primary reaction products. Cyclohexyl-cyclohexene has been identified as a secondary reaction product. The use of high irradiation doses has been shown to lead to decreases in the initial G values of all primary products.

An Experimental Method of Producing Hydroxyapatite

2018 ◽  
Vol 69 (6) ◽  
pp. 1506-1508
Author(s):  
Daniela Jumanca ◽  
Anamaria Matichescu ◽  
Atena Galuscan
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Phosphoric Acid ◽  
Experimental Method ◽  
Oral Hygiene ◽  
Dental Enamel ◽  
Secondary Reaction ◽  
Reaction Products ◽  
Dental Floss ◽  
Main Factor

The main factor in maintaining oral hygiene is first and foremost the correct dental brushing and the use of proper sanitizing means: toothbrush, toothpaste, dental floss, mouthwash. Toothpastes containing hydroxyapatite have an increased efficiency due to the ability to re-mineralize dental enamel. In view of the appearance of the secondary reaction products, the most acceptable variant for HA production is the reaction between calcium hydroxide and phosphoric acid, because it does not result any undesirable side products at a pH ] 9 units. The purpose of this study was to produce and then analyse the HA properties produced experimentally in the SETICO laboratories, using a device derived from the already patented: �Process and device for the production of nano-gels and micro-gels based on alkaline-earthy silicates� issued by OSIM Bucharest on 02.26.2016 No. 128 480.For the analysis of the HA emulsion the following devices were used: The zeta potential analyzer: WALLIS and the VASCO particle size analyser. The contribution of this method is that it provides information and results for the situation where pure hydroxyapatite is used without secondary reaction products. At pH = 7.21 there are particles of ~ 170 nm, very stable (Zeta-potential -133mV) and at pH = 12.64 there are particles of ~ 148nm and more stable (Zeta-potential + 359mV).

Modeling the Time-Dependent Concentrations of Primary and Secondary Reaction Products of Ozone with Squalene in a University Classroom

2019 ◽  
Vol 53 (14) ◽  
pp. 8262-8270 ◽  
Author(s):  
Jianyin Xiong ◽  
Zhangcan He ◽  
Xiaochen Tang ◽  
Pawel K. Misztal ◽  
Allen H. Goldstein
Keyword(s):  
Time Dependent ◽  
Secondary Reaction ◽  
Reaction Products

Lead aspartate: a new en bloc stain for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 34-35
Author(s):  
J.R. Walton
Keyword(s):  
Electron Microscopy ◽  
Calcium Ion ◽  
Enzyme Reaction ◽  
Lead Citrate ◽  
Reaction Products ◽  
En Bloc ◽  
Thin Sections ◽  
Lead Salts ◽  
Thin Sectioning ◽  
High Alkalinity

In electron microscopy, lead is the metal most widely used for enhancing specimen contrast. Lead citrate requires a pH of 12 to stain thin sections of epoxy-embedded material rapidly and intensively. However, this high alkalinity tends to leach out enzyme reaction products, making lead citrate unsuitable for many cytochemical studies. Substitution of the chelator aspartate for citrate allows staining to be carried out at pH 6 or 7 without apparent effect on cytochemical products. Moreover, due to the low, controlled level of free lead ions, contamination-free staining can be carried out en bloc, prior to dehydration and embedding. En bloc use of lead aspartate permits the grid-staining step to be bypassed, allowing samples to be examined immediately after thin-sectioning.Procedures. To prevent precipitation of lead salts, double- or glass-distilled H20 used in the stain and rinses should be boiled to drive off carbon dioxide and glassware should be carefully rinsed to remove any persisting traces of calcium ion.

Studies of Oxide Formation on Copper Thin Films by Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 316-317
Author(s):  
G. G. Hembree ◽  
M. A. Otooni ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Crystal Surface ◽  
Crystal Defects ◽  
Diffraction Reflection ◽  
Reaction Products ◽  
Intermediate Energies ◽  
Crystal Films ◽  
Reflection Electron Microscopy

The formation of oxide structures on single crystal films of metals has been investigated using the REMEDIE system (for Reflection Electron Microscopy and Electron Diffraction at Intermediate Energies) (1). Using this instrument scanning images can be obtained with a 5 to 15keV incident electron beam by collecting either secondary or diffracted electrons from the crystal surface (2). It is particularly suited to studies of the present sort where the surface reactions are strongly related to surface morphology and crystal defects and the growth of reaction products is inhomogeneous and not adequately described in terms of a single parameter. Observation of the samples has also been made by reflection electron diffraction, reflection electron microscopy and replication techniques in a JEM-100B electron microscope.A thin single crystal film of copper, epitaxially grown on NaCl of (100) orientation, was repositioned on a large copper single crystal of (111) orientation.

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