摘要:

AbstractIn order to estimate quantitatively the corrosion of zinc by the loss in weight of metal, corrosion products are removed by immersion of the corroded metal in a cold solution of 10% chromic anhydride to which is added 2% silver chromate and excess (more than 19%) strontium chromate, the whole being kept well stirred. The method, while permitting the removal of heavy deposits of corrosion product, prevents attack on the basis metal such as would be produced by chlorides and sulphates in the deposit in the presence of chromic acid.

ISSN:0021-8871    

DOI:10.1002/jctb.5010010301

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractVarious methods for the synthesis of 3‐ and 4‐methoxystyrene were studied. The decarboxylation of the corresponding methoxycinnamic acids was effected by means of anhydrous copper sulphate in quinoline solution with an improved yi

ISSN:0021-8871    

DOI:10.1002/jctb.5010010302

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractAdsorption of nitrogen and hydrogen on lithium was investigated and the activation energy for nitrogen found to be 47 kg.‐cal./g.‐mol. The addition of other metals promoted adsorption, cerium being found the most effective. The rates of formation of calcium hydride and calcium nitride from the gases and the metal were found at first to increase with temperature up to a maximum and thereafter to decrease. The effect of high pressure on the rates of formation of hydrides and nitrides was also investigated. The possibility of synthesizing ammonia by passing nitrogen and hydrogen, alternately or in admixture, over these metals is discus

ISSN:0021-8871    

DOI:10.1002/jctb.5010010303

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractThe present paper is intended to extend the data in Part I with respect (i) to comparison of the slip‐corrected air‐permeability method with other methods in the normal pigment range, i.e. above o.1 μ., and (ii) to the study of particles below o.1 μ. An absolute comparison is made by using glass microspheres of about 3 μ. diameter. In the case of particles below 0.1 μ., the permeability method remains valid, though formation of plugs in the normal porosity range becomes much more difficult, and, for the very finest particles, it is advisable to replace air by helium, owing to possibilities of adsorption and surface flow of adsorbed mo

ISSN:0021-8871    

DOI:10.1002/jctb.5010010304

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractLead is quantitatively precipitated as basic lead chromate, PbO.PbCrO4, by addition of sufficient potassium chromate, followed by ammonia, to the boiling solution of the lead salt. If a silver salt is also present the silver chromate first formed dissolves in the excess of ammonia. After filtration the silver may be determined as bromide or titrated by a modified Volhard method.

ISSN:0021-8871    

DOI:10.1002/jctb.5010010305

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractMethods which have proved useful in the chemical and infra‐red examination of plasticizers used in polyvinyl chloride (PVC) compositions are summarized. Information is given about the method of isolation of the plasticizer and the qualitative tests which may be applied. On the quantitative side attention is given to the saponification value and the determination of phthalate, phosphate and chlorine. Methods which have proved useful in the isolation of the alcohols derived from ester‐type plasticizers are described.The infra‐red spectra of 19 common plasticizers are presented and the use of these spectra in the identification of plasticizers, and the qualitative and rough quantitative analysis of plasticizer mixtures is described. The examination by infra‐red spectroscopy of extracts from plasticizers, such as alcohols and unsaponifiable material, is described as an aid to identification of plasticizer m

ISSN:0021-8871    

DOI:10.1002/jctb.5010010306

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractRecent improvements in the performance of ion‐exchange resins are illustrated by an account of the preparation and properties of sulphonated cross‐linked polystyrene. The copolymerization of styrene and divinylbenzene (DVB) in bead form is described. Cross‐linked polystyrene has been sulphonated by heating the copolymer with concentrated sulphuric acid at 100°c. in the presence of silver sulphate. After a time depending on the particle size and DVB content of the copolymer, the exchange‐capacity of the product attains a limiting value which corresponds to the formation of a monosulphonic acid. Sulphonated cross‐linked polystyrene is a hygroscopic gel; its swelling and shrinkage in water and aqueous solutions are markedly dependent on the degree of cross‐linking. The cation‐exchange properties of the resin are consistent with those expected of a monofunctional, strongly acidic material. The influence of the extent of cross‐linking on the relative affinity‐coefficients and rates of exchange of sodium and hydrogen

ISSN:0021-8871    

DOI:10.1002/jctb.5010010307

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractCopper in the presence of excess ammonia can be estimated volumetrically by titration at the boil against a glucose solution previously standardized with a copper solution under identical conditions. The method was found useful for the estimation of copper in proofed jute fabrics.

ISSN:0021-8871    

DOI:10.1002/jctb.5010010308

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractPublished results on packed columns and some additional original data on semi‐technical columns filled with Raschig rings are presented in a form permitting correlation of H.E.T.P. values with packing diameter, rate of liquid flow and liquid viscosit

ISSN:0021-8871    

DOI:10.1002/jctb.5010010309

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY