ISSN:0021-8871    

DOI:10.1002/jctb.5010060808

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractMixtures of soil, cement and water will harden sufficiently to be used in place of stone for road‐making, but some soils contain organic matter that can prevent the mixture hardening. The work described is the continuation of an investigation to determine the nature of the organic compounds responsible.Organic matter has been extracted from soil, and split into a number of fractions which have been tested for their ability to retard the hardening of ordinary Portland cement; one fraction has been found to be particularly active in the soil studied.Experiments with pure chemicals have shown that hydroxyl as well as carboxyl groups in organic compounds may be involved in the mechanism of retardation, which is due to absorption of calcium ions liberated during hydration. Tests with a soil developed on a calcareous rock showed that the organic matter in it had no retarding effect, presumably due to the saturation of the active constituent with calcium ion

ISSN:0021-8871    

DOI:10.1002/jctb.5010060801

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe infra‐red spectra of 2: 2′‐dihydroxy‐5: 5′‐dimethydiphenylmethane and of a number of its homologues, of twop‐cresol‐formaldehyde novolak resins, of a trinuclear resole and of related compounds are presented and discussed. Assignments are made for a number of the peaks in the various spectral

ISSN:0021-8871    

DOI:10.1002/jctb.5010060802

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractA medium soft pitch has been oxidized in oxygen at elevated temperature and pressure in the presence of strong alkali to yield a complex mixture of water‐soluble aliphatic acids and aromatic polycarboxylic acids in about 30% yield based on carbon. By chromatography of the methylated hydrocarbons obtained from the acids and from infra‐red spectra, it is concluded that these acids have mainly polynuclear structu

ISSN:0021-8871    

DOI:10.1002/jctb.5010060803

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe preparation of sulphonated coal (resins) from Assam coal (India) has been studied and the optimum conditions for maximum sulphonation have been established. These were heating at 100° with concentrated H2SO4Using a ratio of 1 g. of coal to approx. 4 c.c. of acid in presence of a catalyst, e.g. HgO.The determination of groups responsible for the exchange capacity and estimation of the latter by different methods has also been carried out. The exchange equilibria have also been studied

ISSN:0021-8871    

DOI:10.1002/jctb.5010060804

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe application of infra‐red spectroscopy to the study of the structure of synthetic polypeptides (e.g., poly‐L‐alanine) and silk proteins is disc

ISSN:0021-8871    

DOI:10.1002/jctb.5010060805

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractThe kinetics of toluene and xylene decomposition in the presence of hydrogen have been investigated under two sets of conditions: 500–600°/250 atm. and 700–950°/atmospheric pressure. The reaction is thermal and homogeneous and leads to simple products under these conditions provided that excess hydrogen is initially present. The kinetics are then of order 1.5: first‐order with respect to toluene and order 0.5 with respect to hydrogen. In presence of excess hydrogen, the reaction is straightforward with the formation of benzene and methane. In the absence of excess hydrogen the kinetics and product compositions become complex and variable. Some possible mechanisms for the principal reaction (demethylation) in presence of hydrogen are discussed and attempts are made to explain qualitatively the effect of increased conversion on the reaction sequence postulated by Szwarc for decomposition in the absence of added h

ISSN:0021-8871    

DOI:10.1002/jctb.5010060806

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY

摘要:

AbstractEsterification of epoxy resins with fatty acids at 260° occurs in two stages (1) addition of one fatty acid molecule to an epoxy group to form a hydroxy‐ester, (2) esterification of the original and of the so‐formed hydroxy groups. The curing process of epoxy resins with amines has been studied by infra‐red spectroscopy, and by measurement of the material produced which is non‐extractable by solvents. The combined data provide some indication of the curing m

ISSN:0021-8871    

DOI:10.1002/jctb.5010060807

出版商:John Wiley&Sons, Ltd    

年代:1956

数据来源: WILEY