摘要:

AbstractThe corrosion characteristics of wrought aluminium and a number of wrought and cast alloys when immersed in typical public supply waters under stagnant or slowly moving water conditions have been investigated. Most of the tests have been carried out at room temperature but tests have also been made at temperatures up to 80°. Corrosion‐time curves have been drawn, using pitting depth and loss of weight as measures of corrosion.Changes in the composition of the waters caused greater differences than changes in alloys, but the order of attack was similar in all waters tested. Corrosive attack was most severe in the harder waters, the typical form of attack being the development of deep pits covered by mounds of corrosion product consisting mainly of aluminium hydroxide (‘nodular pitting’)Experiments with synthetic waters have shown that this form of pitting develops when calcium bicarbonate, chlorides, copper salts and dissolved oxygen are present together in the water. These constituents are all normally present in various proportions in public supply waters. A mechanism accounting for the development of the pits is pr

ISSN:0021-8871    

DOI:10.1002/jctb.5010030902

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractChloroanisoles (chlorine substituted in the nucleus) are chlorinated wholly in the side‐chain at 190–200° in the presence of 1/20 molar proportion of phosphorus pentachloride. The three hydrogen atoms of the methoxy group are successively replaced by chlorine, with the formation of the hitherto unknown chlorophenoxymethyl chlorides, chlorophenoxymethylene dichlorides and chloro‐phenoxychloroforms. In the absence of the catalyst a mixture of nuclear‐ and side‐chain‐chlorinated products is formed. With most catalysts other than phosphorus pentachloride chlorination takes place wholly in the nucleus.Unsubstituted anisoles are chlorinated at 190–200° mainly in the nucleus, even in the presence of phosphorus pentachloride, but methyl‐substituted anisoles give mixtures of nuclear‐chlorinated products, methylphenoxymethyl chlorides and meth

ISSN:0021-8871    

DOI:10.1002/jctb.5010030903

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractChlorination of quinol dimethyl ether at 190–195° in the presence of 1/20 molar proportion of phosphorus pentachloride gives mainly nuclear‐substituted products. Chlorination of 2:5‐dichloro‐quinol dimethyl ether under similar conditions takes place wholly in the methoxyl groups. The methoxyl groups are attacked alternately until all six hydrogen atoms are replaced by chlorine. Chlorination of 4:5‐dichloroveratrole gives simil

ISSN:0021-8871    

DOI:10.1002/jctb.5010030904

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

Abstract2:4‐Dichlorophenoxymethyl chloride, obtained by chlorination of 2:4‐dichloroanisole at 190–195° in the presence of 1/20 molar proportion of phosphorus pentachloride, reacts readily at 60° with sodium cyanide or potassium cyanide in acetone or methyl ethyl ketone containing a little water to give 2:4‐dichlorophenoxyacetonitrile, which can be hydrolysed to 2:4‐dichlorophenoxyacetic acid. A little bis‐(2:4‐dichlorophenoxy)methane and 2:4‐dichlorophenol are formed concurrently. The reaction does not proceed satisfactorily in

ISSN:0021-8871    

DOI:10.1002/jctb.5010030905

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractA number of applications of balanced double‐beam systems are described and their special advantages discussed. Such methods have been used for the qualitative study of oils and paints and for the detection and identification of materials separated in chromatographic columns or on specially prepared paper chromatograms. Applications of such methods to quantitative analysis are also discussed and are illustrated by examples of analyses of cordites and lubricating oils. There are indications that the behaviour of oils undergoing oxidation can be followed in this wa

ISSN:0021-8871    

DOI:10.1002/jctb.5010030906

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractWhen Harpe&Van Dorp1first described the preparation of s‐bisdiphenylene‐ethylene by heat treatment of fluorene with lead oxide, they mentioned that the red product was extracted with hot alcohol to free it from ‘resinous material’. We have repeated this work and that of Graebe2and found that, in addition to the products bisdiphenylene‐ethane, bisdiphenylene‐ethylene and fluorenone, there appears a reddish‐brown, high‐melting, benzene‐soluble, alcohol‐insoluble material, the proportion of which depends on the time for which the reactants are maintained at temperatures in the region of 360°. Analysis of fractions obtained by solvent extraction shows that this material consists essentially of the dimeric and trimeric forms of bisdiphenylene‐ethylene. That such polymerization products of bisdiphenylene‐ethylene do, in fact, exist has been shown by heat treatment of the olefinin vacuoat 360°, when dimeric and trimeric derivatives identical with those mentioned above were isolated. (Complex materials, similar in appearance, have also been produced from bisdiphenylene‐ethylene by the action of dimethyl sulphate at 100°.)In an attempt to explain these transformations, a theory based on the formation and polymerization of ‘free radicals’ is advanced, and discussed in relation to the dimerization of other

ISSN:0021-8871    

DOI:10.1002/jctb.5010030907

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010030901

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY