摘要:

AbstractThe yield of itaconic and citraconic acids obtained by laboratory‐scale pyrolysis of anhydrous citric acid can be markedly increased by various catalysts. The best catalyst of those examined was K2HPO4, which, at 5% of the citric acid used, increased the yield of mixed acids from 26% to 64% theoretical at 280°C. There is some indication that the relative proportion of citraconic and itaconic acids is influenced by the catalyst; AlPO3yields a higher proportion of itaconic than K, HPO, but a lower total yield. Each positive catalyst appears to have a more or less strongly marked optimum temperature in the range 240–270deg;c. Increase in batch size, investigated using K2HPO4, was found to diminish the y

ISSN:0368-4075    

DOI:10.1002/jctb.5000690401

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

Abstract2‐Mcthyl‐6‐cthylpyridinc, hitherto not reported as a coal tar constituent, has been isolated from a lutidine fraction of coal tar bases as an zoetrope with proionic acid. Its orientation has been established by oxidation to picolinic acid and by comparison of its ultraviolet absorption spectrum with that of 2 : 6‐l

ISSN:0368-4075    

DOI:10.1002/jctb.5000690402

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractDispersions of a bituminous coal in phenanthrene were examined by X‐ray powder photography. A characteristic diffraction pattern was observed which was found to be identical with that given by partly amorphous abietic acid and aluminium and ferric abictates. No reliable estimate of the concentrations of these constituents could be made, but qualitative observations indicated that they arc minor constituent

ISSN:0368-4075    

DOI:10.1002/jctb.5000690403

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractIn the article titled “Some preliminary investigations of the phenol‐formaldehyde reaction” by Dr. T. T. Jones (J. Soc. chem. Ind.1946,65, 264), this statement is made in the summary: “In alkaline media, dialcohols also seem to be produced more readily, as indicated by the fact that a first order rate law is obeyed until about 45% of the formaldehyde bas r

ISSN:0368-4075    

DOI:10.1002/jctb.5000690404

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractA method has been developed for the examination of compositions prepared from polyvinyl chloride and related polymers. Its purpose is to recover the polymer from the. composition by solution in tetrahydrofuran, followed by subsequent precipitation of the polymer with alcohol from the tetrahydrofuran solution.Figures are given for the chlorine contents of polymers used in the preparation of compositions and of the corresponding polymers recovered from tetrahydrofuran solution; the influence of the test on the infra‐red spectra of the polymers is indicate

ISSN:0368-4075    

DOI:10.1002/jctb.5000690405

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe British Pharmacopoeia requires ichthammol to be miscible with fixed oil, whereas the French Codex requires it to be immiscible. Investigation has shown that ichthammol containing about 50% water is emulsifiable with fixed oils only under certain conditions, and that the pharmacopoeial requirement needs amendment. The sulphur contents of ichthyol and ichthammol have been studied and it has been found that the sulphide‐ and thiophen‐sulphur are reduced by sulphonation. No connexion has so far been found between the sulphur distribution of samples of ichthammol and their bactericidal activ

ISSN:0368-4075    

DOI:10.1002/jctb.5000690406

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractDetailed growth curves based on progressive turbidity readings have been used to study the inhibition ofAerobacter aerogenesType I, by a series of alkyl 4‐hydroxybentoates. Results in the lag phase are irregular, but it is apparent that the elongation of this phase becomes very marked at the higher concentrations of the inhibitor and that complete inhibition of growth occurs at a concentration that extends lag indefinitely rather than at one which reduces the growth rate to zero. Inhibition in the logarithmic phase, plotted as a function of inhibitor concentration, gives curves convex to the abscissa that contrast with experience of fungi, where characteristic concave adsorption forms have been obtained. However, the convexity of the present series of curves is likely to be a reflection of secondary effects associated with this method of determining bacterial inhibition, particularly in that there is a loss of viability in cells exposed to the higher concentrations. Determinations based on stationary populations arc convenient and give good agreement between experiments, but are not necessarily related in any simple fashion to growth rate inhibition.Although the order of increasing activity with increasing chain length of the esters is similar that found for fungi the activity of the methyl ester is less againstAerobacter aerogenesso that solubility difficulties soon prevent the attainment of a reasonable level of inhibition.Growth curve methods that use a relatively small inoculum with consequent lag phase of variable length do not appear well suited for a direct study of growth rate inhibition.Growth curve method that use a relatively small inoculum with consequent lag phase of variable length do not appear well suited for a direct study of growth rate inhibition. A simple method better suited to this purpose is being develope

ISSN:0368-4075    

DOI:10.1002/jctb.5000690407

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractPolythene of molecular weight 11,000 to 22,000 on exposure to bright sunlight undergoes deterioration resulting in embrittlement and degradation of electrical and mechanical properties. Deterioration is thought to be due to photocatalysed oxidation and this per describes a study of deterioration by artificial ageing. Curves relating power factor to oxygen absorption arc shown. The ultra‐violet absorption spectrum shows that the attack is probably due to the presence of carbonyl groups as an impurity in the polythene.The effect of antioxidant addition was followed by folding endurance tests. Infra‐red absorption spectra between 2.5μ. and 15μ. have been mapped before and after irradiation and the presence of hydroxyl, carbonyl and carboxyl groups established. The photochemical mechanism has been discussed and it is thought that the carbonyl groups are responsible for initiating the deterior

ISSN:0368-4075    

DOI:10.1002/jctb.5000690408

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractThe influence of metal cations of the typical and transitional series in catalytic oxidation of oleic acid has been investigated over a wide range of conditions. The results of a series of oxidations, in which the catalyst metal ion content was adjusted to a constant value, have afforded new information concerning the intrinsic effect of metal ions on oxygen absorption by mono‐ethenoid acids.A new relative order of efficiency of metal cation catalysts in autoxidation processes has been obtained. The catalytic activity of the metal ions is correlated with their atomic structure and is shown to be a periodic function. A theory of catalytic activity is advanced applicable to metals used for promoting gaseous oxidation of unsaturated fatty acids and esters, and for the oxidation of parent oil

ISSN:0368-4075    

DOI:10.1002/jctb.5000690409

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY

摘要:

AbstractWhen the middle oils obtained from the hydrogenation of coal were hydrogenated at 450° and 475° c. in a stainless‐steel autoclave in the absence of any added catalyst, very little of the phenolic material was convened to neutral products. Whereas the original material contained only 2·9%, phenols boiling below 230° c., the hydrogenated product (at 475° c.) contained 9·1% (based on the charge) phenols boiling below this temperature. When the phenolic fraction of the middle oil was isolated before hydrogenolysis and then treated, more conversion of high‐boiling to low‐boiling phenols occurred, but this was accompanied by elimination of oxygen and the production of about 20% neutr

ISSN:0368-4075    

DOI:10.1002/jctb.5000690410

出版商:John Wiley&Sons, Ltd    

年代:1950

数据来源: WILEY