Vulcanization of Rubber in the Presence of meta-Dinitrobenzene

1938 ◽  
Vol 11 (2) ◽  
pp. 319-330
Author(s):  
J. M. Wright ◽  
B. L. Davies
Keyword(s):  
Nitrogen Content ◽  
Binary Mixtures ◽  
Boiling Point ◽  
Complex Mixtures ◽  
Oxygen Analog ◽  
Consecutive Reactions ◽  
Rate Of Reaction ◽  
Sulfur Vulcanization ◽  
Time Required ◽  
Additive Compound

Abstract Since Ostromislensky (J. Russ. Phys. Chem. Soc., 49, 1456 (1916)) claimed that vulcanization of rubber in the presence of m-dinitrobenzene entailed the addition of oxygen to the rubber molecule, it has been suggested that this form of vulcanization may be the oxygen analog of ordinary sulfur vulcanization. Blake (Ind. Eng. Chem., 22, 740 (1930)), however, extracted vulcanizates with acetone and determined the nitrogen content. If it were assumed that the unextractable nitrogen was combined with the rubber, the figures indicated that the chemical reaction was monomolecular, and in explanation it was suggested that consecutive reactions occurred, one of which was slow. The vulcanizate was concluded to be an additive compound of the vulcanizing agent with the rubber. Objects and Technic.—The objects of the present work were to answer two questions: (1) what are the reactants, and (2) in what manner do they react? It was hoped with the simplest binary mixtures to find what were the essential ingredients, and to proceed to increasingly complex mixtures to discover the roles of the various accessory substances. By vulcanization in solution it was found that the examination of the final reaction mixture was facilitated. The mixes were therefore dispersed in technical xylene, of boiling point 140° C., and vulcanized by boiling. At a particular stage, the rubber became insoluble, and the time required to arrive at this stage was a characteristic of the mix and was taken to be proportional to the rate of reaction.

Inhibition of Radical-Initiated Vinyl Acetate Polymerisation by Tobacco Smoke Fractions

1974 ◽  
Vol 7 (5) ◽  
Author(s):  
M.A. Nisbet ◽  
S. Schmeller
Keyword(s):  
Benzoyl Peroxide ◽  
Vinyl Acetate ◽  
Tobacco Smoke ◽  
Boiling Point ◽  
Water Bath ◽  
Measuring Time ◽  
Time Required

AbstractBoth the vapour and particulate phases of tobacco smoke have been shown to retard benzoyI-peroxide-initiated polymerisation of vinyl acetate by interception of the radicals involved in the polymerisation process. The extent of inhibition of polymerisation by test compounds is estimated by measuring time taken for a mixture of monomer and benzoyl peroxide, immersed in a water-bath at 70°C, to reach a spontaneous boil and comparing it with the time required for a similar mixture with added retarder to reach boiling point. Units are expressed as minutes of inhibition per part per million of inhibitor × 10

scholarly journals The Mixtures of 2.4-Dinitrophenylhidrazones of Inferior Carbonyl Compounds and their HPLC Separation with Gradient Binary Mixtures Phases

2008 ◽  
Vol 3 (1) ◽  
pp. 52-55
Author(s):  
Gheorghe Zgherea
Keyword(s):  
Liquid Chromatography ◽  
Acid Solution ◽  
Organic Compounds ◽  
Binary Mixtures ◽  
Organic Solvents ◽  
Boiling Point ◽  
Carbonyl Compounds ◽  
Hplc Separation ◽  
Reverse Phase ◽  
Theoretical Considerations

Mixtures of small quantities of carbonyl compounds are presents in foods, concerning sensorial qualities. The inferior carbonyl compounds (C2-C4, boiling point <100°C) – mono and dicarbonyl – can be identified and measured their concentrations, after a separation by distillation on the water bath. They are transferred in a strongly acid solution of 2.4-dinitrophenylhidrazine (2.4-DNPH), generating a mixture of insoluble 2.4-dinitrophenylhidrazones (2.4-DNPH-ones). The 2.4-DNPH-ones are organic compounds with weak polarity, solids, crystallized, yellows and water insoluble, soluble in organic solvents. The mixture of 2.4dinitrophenylhidrazones may be separated by liquid chromatography, using the reverse phase mechanism [1-3]. This paper contains experimental and theoretical considerations to the means of separation through liquid chromatography of two synthetically and a natural mixtures that contain 2.4-DNPH-ones provided by inferior carbonyl compounds; to obtain conclude results, in the synthetically mixtures was introduce and 2.4-DNPH-ones provided by carbonyl compounds having three (acetone and propanal) and four (isobutyl aldehyde) atoms of carbon.

scholarly journals An account of certain new facts and observations on the production of steam

1837 ◽  
Vol 3 ◽  
pp. 123-123
Keyword(s):  
Boiling Point ◽  
Dense Cloud ◽  
Complete Evaporation ◽  
Series Of Experiments ◽  
Time Required ◽  
Heated Metal

Having observed that water on the surface of melted iron was very slowly affected by the heat, although it exploded violently when the same fused metal was dropped into it, the author made a series of experiments on the time required for the evaporation of the same quantity of water successively poured into a massive iron cup, at first raised to a white heat, and then gradually cooled by the addition and evaporation of the water. The first measures of water were longer in being evaporated than those subsequently added, in consequence of the reduction in the temperature of the iron, until this temperature reached what the author calls the evaporating point , when the water was suddenly thrown oft in a dense cloud of steam. Below this temperature, the time required for the complete evaporation of the same measure of water became longer in proportion as the iron was cooler, until it fell below the boiling point. The author accounts for these results from the circumstance that when the metal is at the higher temperatures, the water placed on its surface is removed from contact with it by a stratum of interposed steam. From these and other experiments, he is led to infer the necessity of keeping water in close and constant contact with the heated metal in which it is contained, in order to obtain from it, in the shortest time, the greatest quantity of steam.

The Effect of Vapor Polarity and Boiling Point on Breakthrough for Binary Mixtures on Respirator Carbon

AIHAJ ◽  
1996 ◽  
Vol 57 (8) ◽  
pp. 717-723 ◽  
Author(s):  
Coreen A. Robbins ◽  
Patrick N. Breysse
Keyword(s):  
Binary Mixtures ◽  
Boiling Point

scholarly journals Similarity and strength of glomerular odor representations define neural metric of sniff-invariant discrimination time

2018 ◽  
Author(s):  
Anindya S. Bhattacharjee ◽  
Sasank Konakamchi ◽  
Dmitrij Turaev ◽  
Roberto Vincis ◽  
Daniel Nunes ◽  
...  
Keyword(s):  
Binary Mixtures ◽  
Euclidean Distance ◽  
Activity Patterns ◽  
Fast Time ◽  
Breathing Frequency ◽  
Sampling Behavior ◽  
Neuronal Processing ◽  
Measure Of Similarity ◽  
Time Required ◽  
Intrinsic Imaging

AbstractThe olfactory environment is first represented by glomerular activity patterns in the olfactory bulb. It remained unclear, how these activity patterns intersect with sampling behavior to account for the time required to discriminate odors. Using different classes of volatile stimuli, we investigated glomerular activity patterns and sniffing behavior during olfactory decision-making. Mice discriminated monomolecular odorants and binary mixtures on a fast time scale and learned to increase their breathing frequency at a fixed latency after trial initiation, independent of odor identity. Relative to the increase in breathing frequency, monomolecular odorants were discriminated within 10-40 ms while binary mixtures required an additional 60-70 ms. Intrinsic imaging of odor-evoked glomerular activity maps in anesthetized and awake mice revealed that the Euclidean distance between glomerular patterns elicited by different odors, a measure of similarity and activation strength, was anti-correlated with discrimination time. Therefore, the similarity of glomerular patterns and their activation strengths, rather than sampling behavior, define the extent of neuronal processing required for odor discrimination, establishing a neural metric to predict olfactory discrimination time.

scholarly journals Electro-olfactogram and multiunit olfactory receptor responses to complex mixtures of amino acids in the channel catfish, Ictalurus punctatus.

1991 ◽  
Vol 98 (4) ◽  
pp. 699-721 ◽  
Author(s):  
J S Kang ◽  
J Caprio
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Binary Mixtures ◽  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
Olfactory Receptor ◽  
Complex Mixtures ◽  
Neutral Amino Acids ◽  
Acidic Amino Acids ◽  
Receptor Sites

In vivo electrophysiological recordings from populations of olfactory receptor neurons in the channel catfish, Ictalurus punctatus, clearly showed that both electro-olfactogram and integrated neural responses of olfactory receptor cells to complex mixtures consisting of up to 10 different amino acids were predictable with knowledge of (a) the responses to the individual components in the mixture and (b) the relative independence of the respective receptor sites for the component stimuli. All amino acid stimuli used to form the various mixtures were initially adjusted in concentration to provide approximately equal response magnitudes. Olfactory receptor responses to both multimixtures and binary mixtures were recorded. Multimixtures were formed by mixing equal aliquots of 3-10 different amino acids. Binary mixtures were formed by mixing equal aliquots of two equally stimulatory solutions. Solution 1 contained either one to nine different neutral amino acids with long side-chains (LCNs) or one to five different neutral amino acids with short side-chains (SCNs). Solution 2, comprising the binary mixture, consisted of only a single stimulus, either a LCN, SCN, basic, or acidic amino acid. The increasing magnitude of the olfactory receptor responses to mixtures consisting of an increasing number of neutral amino acids indicated that multiple receptor site types with highly overlapping specificities exist to these compounds. For both binary mixtures and multimixtures composed of neutral and basic or neutral and acidic amino acids, the receptor responses were significantly enhanced compared with those mixtures consisting of an equal number of only neutral amino acids. These results demonstrate that receptor sites for the basic and acidic amino acids, respectively, are highly independent of those for the neutral amino acids, and suggest that a mechanism for synergism is the simultaneous activation of relatively independent receptor sites by the components in the mixture. In contrast, there was no evidence for the occurrence of mixture suppression.

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