bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymerisation of dec‐1‐ene. II. Effect of reaction temperature
Authors: Beynon K. I. , Milne C. B. , Southern D. 
Published: July 2010

AbstractThe effect of temperature on the polymerisation of dec‐1‐ene has been studied, the catalysts used being (a) a catalyst prepared by mixing triethylaluminium and titanium tetrachloride at a molar ratio of 0.3:1 and (b) aluminium chloride. Polymers prepared at room temperature with triethylaluminium/titanium tetrachloride contain an average of one double bond per molecule. Increase in temperature from 20 to 150° produces saturated polymers of higher viscosity. The loss of olefinic unsaturation is due to cyclisation reactions, which produce aromatics and cycloalkanes, and to disproportionation reactions. An increase in reaction temperature from 20 to 150° with aluminium chloride as catalyst has little effect other than to reduce the viscosity of the polymer. The polymers produced at high temperatures by both catalyst systems are very similar. It is concluded that the active catalyst species in the triethylaluminium/titanium tetrachloride system at 150° is aluminium chloride or a complex containing it.
Compressibility of linear polymers
Authors: Warfield R. W. 
Published: July 2010

AbstractBulk compressibilities of a series of six linear polymers have been measured at pressures up to 16,000 atmospheres and over the temperature range 21° to 193°. All the polymers exhibited non‐linear pressure vs. change in volume isotherms. In a few cases the polymers exhibited pressure‐induced glass transitions. The coefficient of compressibility at one atmosphere usually increases with increasing temperature. at about 25° most polymers exhibit compressibilities of the order of 10 to 15%. The nature of the observed compressibilities is discussed in relation to the free volume of the system.
Low‐temperature oxidation of p‐xylene in liquid phase using acetaldehyde as accelerator. I. Stirred tank reactor
Authors: Yamamoto Masatoshi , Minoda Takahiko , Nishino Hiroshi , Imoto Tatsuya 
Published: July 2010

AbstractThe oxidation of p‐xylene in the presence of acetaldehyde as accelerator and cobalt acetate as catalyst at 60–100° was studied using a semi‐batch process in a stirred reactor. Better yields of terephthalic acid (up to 98%) were given than with other methods although the operation was similar. Diffusion was the rate‐determining step, and possibilities for improving reaction rate are discussed.
Interaction effects between the constituents of carbon artefacts during graphitisation
Authors: Richards B. P. , Kellett E. A. , Mason I. B. 
Published: July 2010

AbstractA crystallographic study, using X‐ray diffraction techniques, has been made of the interaction effects between the constituents of coke‐binder artefacts when heat‐treated to graphitising temperatures. It is shown that petroleum and pitch cokes graphitise to a greater extent separately than when combined in petroleum coke/pitch binder artefacts, but for artefacts based entirely on either petroleum or pitch, this effect of the binder in retarding graphitisation of the grist coke is very much less.
Development of new initiators for polymerisation reactions
Authors: Ledwith A. 
Published: July 2010

AbstractThe development of simple, stable, and well defined catalyst systems for the initiation of ionic polymerisation is reviewed. The principles involved are illustrated by reference to the use of potassium t‐butoxide in dimethyl sulphoxide for initiating anionic polymerisation of ethylene oxide and of the hexachloroantimonate salt of the triphenyl methyl cation for polymerisation of tetrahydrofuran. Other stable organic cations initiate polymerisation via charge transfer complexes and can give rise to cation‐radicals as intermediates. It is suggested that related cation‐radicals may play a role in lignin biosynthesis.
Role of carboxyl groups in water absorption by keratin
Authors: Watt I. C. , Leeder J. D. 
Published: July 2010

AbstractThe contribution of carboxyl groups to the water sorbing properties of keratin has been investigated over the complete water vapour pressure range. A series of partially methylated wools were studied: below 80% R.H. there is a reduction in water content linear with the reduction in the number of carboxyl groups, but at humidities above 80% R.H. extra water is absorbed because of disruption of the structural network under the acid conditions of treatment.Extrapolation of the plot of equilibrium water content vs. free carboxyl group content of partially methylated wool samples at a particular humidity. made at several humidity values, enables an isotherm to be deduced for wool containing no COO groups. The reduction of water content for wool of zero carboxyl group content, as a function of relative humidity, represents the isotherm attributable to the free carboxyl groups in keratin; this is a simple Langmuir isotherm at low humidities. The reduction of water content is proportionately greater at lower humidities—at 5% R.H., 36% of the total water and at 65% R.H., 22% of the total water absorbed by keratin is associated with free carboxyl groups. The number of water molecules associated with each carboxyl group is greater than previous literature values.
Influence of aluminium hydroxide and lime on the hydration of tricalcium silicate
Authors: de Jong J. G. M. , Stein H. N. , Stevels J. M. 
Published: July 2010

AbstractExperiments by isothermal calorimetry, indicate that the hydration of 3CaO·SiO2 (C3S) is influenced very little by gibbsite; it is influenced by bayerite to a somewhat larger extent.In the presence of amorphous Al(OH)3 the reaction of C3S with water shows a very complicated course and gives four heat peaks. If CaO is added in addition to this Al(OH)3, the third and the fourth heat peaks are more pronounced. From qualitative d.t.a., infra‐red, electron‐microscope and X‐ray investigations, as well as from quantitative X‐ray analysis, a reaction mechanism is proposed.The quantity of C3S reacted, determined by means of quantitative X‐ray analysis, is greater during the reaction of 2·00 g C3S with 0·40 g amorphous Al(OH)3, 0·08 g CaO and 2·00 ml water, than during the reaction of 2·00 g C3S with 2·00 ml water.
Isobaric ternary vapour‐liquid equilibria system: Benzene‐cyclohexane‐n‐butanol
Authors: Subbarao B. V. , Ventakarao C. 
Published: July 2010

AbstractVapour/liquid equilibrium data for the system, benzene‐cyclohexane‐n‐butanol, were obtained at 760 ± 1 mm Hg pressure using a modified Colburn equilibrium still. No ternary azeotrope was observed. The experimental activity coefficient data were correlated with Wohl's three‐suffix symmetrical and three‐suffix Margules equations with and without using a ternary constant. From an estimate of the average errors in Y1, Y2, and Y3, Wohl's three‐suffix Margules equations seem to fit the data fairly well using a ternary constant, C = −0.1042. From the equilibrium curve drawn for the ternary system on a n‐butanol‐free basis with percent, n‐butanol as parameter, it was found that the azeotrope disappeared at 90–95% n‐butanol.
Formation and reactivity of nitrides II. Calcium and magnesium nitrides and calcium cyanamide
Authors: Glasson D. R. , Jayaweera S. A. A. 
Published: July 2010

AbstractSamples of calcium and magnesium nitrides have been prepared and hydrolysed ‘dry’ with water vapour and steam or ‘wet’ with liquid water. Changes in phase composition, surface area, crystallite and aggregate sizes have been correlated with hydrolysis conditions and compared with ‘dry’ and ‘wet’ hydration of lime and magnesia. The reactions involve the splitting of nitride and oxide crystallites and the subsequent ageing of the newly formed calcium and magnesium hydroxides.Hydrolysis of calcium cyanamide has been studied similarly. The intermediate product, hydrated lime, has been separately reacted with urea solutions and gives calcitic rhombs having a wide crystallite size range.
Preparation of the oleic acid/sulphur dichloride adduct and some derivatives
Authors: Nooi J. R. , Huijben G. J. 
Published: July 2010

AbstractThe preparation of the sulphur dichloride/oleic acid adduct in high yields is described.The reactivity of the chlorine atoms in the adduct in nucleophilic substitution reactions is demonstrated. Particularly noteworthy is the formation of a factice‐like polyester in almost quantitative yield when the adduct is heated with sodium hydroxide solution.Some derivatives of the adduct have been converted into polyamides.
Separation of o‐ and p‐ chlorotoluene by solvent extraction
Authors: Hanson C. , Patel A. N. , Chang‐Kakoti D. K. 
Published: July 2010

AbstractPhase equilibrium data are presented for o‐ and p‐chlorotoluene distributed between n‐heptane and aq. methanol (95 vol.‐%), ‘Sulfolane’ and dimethyl sulphoxide (DMSO) and used to evaluate the possibility of employing distribution between these solvents as a means of separating a mixture of the isomers.
Preparation and properties of some acyloxysilanes
Authors: Emblem H. G. , Hargreaves K. , Oxley C. E. 
Published: July 2010

AbstractAcyloxy derivatives of silicon were prepared by the interchange reaction between carboxylic acids (including various grades of palmitic acid) and tetraethoxysilane, and by the interchange reaction between palmitic acid and technical ethyl silicate (silica content 40%) or technical isopropyl silicate (silica content 38%). In most of the reactions, sodium methoxide was used as catalyst. Some physical properties of the reaction products were determined, and the materials made from palmitic acid were evaluated as water‐repellent coatings on cotton cloth.
Kinetics of the dissolution of uranium dioxide in nitric acid. I
Authors: Shabbir Muhammed , Robins R. G. 
Published: July 2010

AbstractThe kinetics of the dissolution of uranium dioxide in nitric acid have been investigated over a range of acid concentration from 0·3 to 37·0 molal. A change in the reduction mechanism for nitric acid is indicated at about 16 molal concentration.A proposed mechanism for the initial rate period of dissolution is consistent with experimental results and with the known thermodynamics of the system.
Changes in surface characteristics of compacted coal during isothermal decomposition
Authors: Broadbent D. , Dollimore D. , Dollimore J. 
Published: July 2010

AbstractIsothermal decomposition of coal compacts was carried out in nitrogen between 200–700°, and weight loss was recorded against time. Surface area changes, measured by nitrogen adsorption, were determined at 300° and 500°. The porous structure of the coal disappeared for a while during the decomposition owing to blocking of the pores by tarry matter. The surface area then increased when this tarry matter was driven off.
VApour‐liquid equilibria systems: Hexane‐hexylalcohol and heptane‐hexylalcohol
Authors: Rao P. Ramachandra , Chiranjivi C. , Dasarao C. J. 
Published: July 2010

AbstractIsobaric vapour‐liquid equilibrium data have been determined for the binary systems hexane‐hexylalcohol and heptane‐hexylalcohol at 760 mm of Hg total pressure, using a Scatchard and Ticknor still. The isobaric vapour‐liquid equilibria of both the systems have been correlated satisfactorily by the equations of Redlich & Kister as modified by Chao despite the wide variation in boiling points.Ewell et al.1 have classified liquids into five groupings based on their properties of forming hydrogen bonds. According to this classification, hydrocarbon‐alcohol combinations involve breaking of hydrogen bonds and always show positive deviations. A systematic study of the vapour‐liquid equilibrium data of these has been attempted and the present work presents the results.
Gelation of casein formaldehyde as influenced by the presence of sodium metasilicate and sodium hexyl sulphate
Authors: Malik W. U. , Agarwal S. K. 
Published: July 2010

AbstractConcentrated solutions of casein (5·5–6·0%), modified by the addition of formaldehyde, undergo rapid gelation in the presence of sodium metasilicate and sodium hexyl sulphate. This gelation occurs more readily when a mixture of both is used. The presence of an extremely small amount of either of the reagents with the other decreases the time of gelation considerably. The role of different constituents of the gelation mixture is discussed. The use of sodium metasilicate containing small amounts of sodium hexyl sulphate to replace sodium aluminate in the manufacture of casein fibres is suggested.
Bacterial degradation of plasticised PVC‐effect on some physical properties
Authors: Booth G. H. , Robb J. A. 
Published: July 2010

AbstractBurial tests on plasticised PVC in neutral soil inoculated with species of Pseudomonas and Brevibacterium have shown degradation in 8 weeks that is largely dependent on the nature of the plasticiser. There was no evidence for any attack on the polymer itself. Phthalate and phosphate plasticisers were resistant; adipate, azelate and sebacate plasticisers were susceptible and a number of others, e.g. chlorinated hydrocarbon and epoxy types, occupied an intermediate position. The degree of attack was also dependent on the nature of the stabiliser used in the PVC formulation, lead‐based stabiliser conferring less resistance than barium/cadmium‐based stabiliser. Degradation has been assessed in terms of loss in weight, change of stiffness and loss of energy during cyclic deformation.
Ion‐exchange properties of brown algae. II. Rate mechanism for calcium‐hydrogen ion exchange for particles from Ascophyllum nodosum
Authors: Myklestad S. 
Published: July 2010

AbstractThe ion‐exchange properties of algal particles from A. nodosum have been investigated. The Ca/H ion‐exchange rate at hydrogen ion concentration 0·1 n was shown to be strikingly lower, while the selectivity coefficent K was about ten times higher, for A. nodosum than for L. digitata and L. hyperborea stipe particles. Log K showed a marked decrease with increasing calcium equivalent fraction in the algal particles. The higher Ca/H selectivity of algal particles from A. nodosum was shown to be the cause of the observed difference in exchange rate between this alga and the two other species.The ion‐exchange rate Ca/H for 36–52 mesh particles from A. nodosum at hydrogen ion concentration 0·1 n was governed by a film‐diffusion mechanism and the diffusion of calcium through a thin liquid film enveloping the particles was suggested as the rate‐determining step. The rate was particle‐diffusion controlled for 10–20 mesh particles. The exchange rate for 36–52 mesh particles increased strongly as the hydrochloric acid concentration was increased from 0·05 to 1 n; this exchange appeared to proceed like a second order reaction at 0·05 n and showed a gradual change to a first order reaction at 1 n‐acid.
Reaction of azo derivatives of acetoacetanilide with aliphatic amines
Authors: Topham A. 
Published: July 2010

AbstractAzoacetoacetanilides condense with primary aliphatic amines to give azoaminocrotoanilides (I). Comparison of the infra‐red and nuclear magnetic resonance spectra with those of model compounds leads to the proposal of formulae of type (VI) as a refinement of formula (I).magnified image
Preparation of N‐cyclohexylbenzothiazole‐2‐sulphenamide by oxidative condensation
Authors: Banks D. J. , Wiseman P. 
Published: July 2010

AbstractIt has been shown that in the preparation of N‐cyclohexylbenzothiazole‐2‐sulphenamide by the reaction of 2‐mercaptobenzothiazole with cyclohexylamine in the presence of sodium hypochlorite, N‐cyclohexyl‐benzothiazole‐2‐sulphonamide, sodium benzothiazole‐2‐sulphonate, benzothiazole‐2‐sulphonyl chloride, 2,2′‐dithiobisbenzothiazole, and probably sodium benzothiazole‐2‐sulphinate can be formed as by‐products, in amounts depending on pH, temperature and amount of amine used. Mechanisms are suggested for the reactions involved.
Symmetrical‐area tests for the consistency of vapour–liquid equilibrium data. I. Isothermal data
Authors: Herington E. F. G. 
Published: July 2010

AbstractThe need to test experimentally determined vapour–liquid equilibrium data for thermodynamic consistency is now widely recognised. This paper is concerned with general integral tests based on the Duhem–Margules equation and not with particular algebraic solutions of that equation. A family of ‘symmetrical‐area’ tests is presented; these new tests are more powerful tools for the examination of experimental data than the area tests previously developed by the author, and can be used to examine part of a composition range and to identify regions of poor observation. Moreover, the tests can sometimes be used to identify the quantities that are in error. They are applicable to systems with miscibility gaps.
Solution chemistry of the electrochemical machining of titanium, niobium and tantalum
Authors: Rolsten R. F. 
Published: July 2010

AbstractIn the electrochemical machining process the electrolyte, in addition to conducting the required current, has the added function of removing the electrode reaction products—hydrogen from the cathode and metal oxide from the workpiece. This function is facilitated if close control is maintained over the pH of the electrolyte. Titanjum halides form clear solutions if the pH is less than 2 but precipitate if the pH exceeds 3·7. Niobium and tantalum halides were also studied.
Oxidation of thiols in gas‐liquid systems. II. Reaction in the presence of added metal catalysts
Authors: Cullis C. F. , Hopton J. D. , Swan C. J. , Trimm D. L. 
Published: July 2010

AbstractComparisons have been made of some kinetic features of the oxidation in alkaline solution of a series of simple aliphatic and aromatic thiols in the presence of added metal catalysts. With ethanethiol as the reactant, the catalytic activity of a wide variety of metals, added to the solution as simple salts, has been determined. Furthermore, using three typical metal catalysts, the oxidation of a series of thiols has been investigated and an attempt has been made to correlate rates of oxidation with the geometric structure and electron‐directing properties of the organic groups present. The size of such groups has been found to be one of the most important factors controlling the overall rate of oxidation.
Kinetics of the reduction of silicon tetrachloride and trichlorosilane by hydrogen
Authors: Ashen D. J. , Bromberger G. C. , Lewis T. J. 
Published: July 2010

AbstractReaction products from SiCl4/H2 and SiHCl3/H2 mixtures have been examined over the temperature range 800–1200°K, and the conditions under which equilibrium is reached have been established. The results point to a ΔH° for SiCl4 of between −162 and −163 kcal/mole. The reaction rates expressed in mole/1/sec were: d[SiHCl3]/dt = 7.8 × 1010 [SiCl4] [H2]1/2 exp −55,000/RT and d[SiH2Cl3]/dt = 2.0 × 1010 [SiHCl3] exp −51,000/RT and kinetic mechanisms have been suggested.
New low‐density ceramic material for packing fractional distillation columns. II
Authors: Castellucci N. T. , Krouskop N. C. 
Published: July 2010

AbstractThe paper compares the new, spherical, low‐density ceramic material described in Part I with other packing materials having different geometries. The increased separating power of the new material is due to different liquid flow patterns, spreadability, accessible surface area and surface morphology. Although each of these terms has a distinctive meaning which cannot be employed without some reference to the other two, the first three terms are often erroneously used interchangeably throughout the literature. In this paper, these terms are more accurately defined and used in accordance with experimental evidence.
Distribution of sulphuric acid between tri‐n‐butyl phosphate and water
Authors: Hanson C. , Patel A. N. 
Published: July 2010

AbstractThe distribution of sulphuric acid between water and 40% by vol. solutions of tri‐n‐butyl phosphate (TBP) in six diluents, and also between water and 40, 60 and 80° solutions of TBP in cyclohexane at 20°, and between water and 40% solution of TBP in cyclohexane and pure TBP at 20°, 30° and 50° has been studied to find the effects of temperature, diluent and TBP concentrations on the extractability of sulphuric acid and on ‘third‐phase formation’.
Fischer‐tropsch waxes. I. An infra‐red method for the determination of crystallinity
Authors: le Roux J. H. 
Published: July 2010

AbstractCrystallinity is, ideally, the fraction or percentage of perfectly crystalline matter in a material which is partially crystalline. Because transition structures can exist, however, measured crystallinity will depend largely on the method used.The differences in the infra‐red spectra of the same substance in the crystalline and amorphous states can be exploited for quantitative measurement. Methods based on bands that appear only in the ‘amorphous spectrum’, such as the method described here, have definite advantages over those based on ‘crystalline bands’. While testing the method it was found that the rate of cooling has only a small effect on the crystallinity of Fischer–Tropsch waxes. Surface effects play an important role, however. Thin slices cut from the central parts of thick discs were used for measurements. Before they were sampled, certain waxes had to be homogenised by melting. Results were reproducible within ± 1·5 to ±6 per cent for different waxes. Because of the dependence of crystallinity upon the method used, however, the value of this method lies in its use in comparative studies.
Formation and reactivity of oxides and basic salts. III. Titanium dioxides and basic titanic salts
Authors: Glasson D. R. , Johnson J. S. , Sheppard Margaret A. 
Published: July 2010

AbstractMethods of production and application of titanium dioxides and basic titanic salts have been summarised and the appropriate physical properties of the products have been studied. Variations in phase composition, surface area and crystallite and aggregate sizes have been correlated with experimental conditions.When titanic sulphate or chloride is hydrolysed by sodium hydroxide, the basic salts initially formed are decomposed subsequently to hydrous titanium dioxide as the pH becomes stabilised at higher values. The specific surface of the basic sulphate increases considerably when it hydrolyses to anatase. On calcination at temperatures up to about 750°, the anatase crystallites can grow from about 0·006 μm to the requisite 0·1–0·5 μm range, but the aggregate sizes vary widely. Shock‐heating at temperatures between 600° and 900° removes the remaining water and breaks up the larger aggregates.At higher temperatures, the anatase is transformed to rutile which subsequently sinters. The rutile produced by shorter calcinations at 1100°–1150° is similar in crystallite size to that obtained by complete oxidation (‘burning’) of titanic chloride vapour at the same temperatures. Results emphasise the need for close control of residence time in the high‐temperature zone in the production of pigmentary titanium dioxide.
Precipitate flotation. IV. Flotation of silver, uranium and gold
Authors: Mahne E. J. , Pinfold T. A. 
Published: July 2010

AbstractThe conditions for the flotation of silver using α‐nitroso‐β‐naphthol and β‐nitroso‐α‐naphthol, that of uranium using α‐nitroso‐β‐naphthol and benzoylacetone, and that of gold using phenyl‐α‐pyridylketoxime were examined. Recoveries of over 90% were possible from 5 × 10−5 M solutions of silver, 10−4 M solutions of uranium (VI) and 3 × 10−4 M solutions of gold (III). Extractions were best in the pH range 7–9, 6–9 and 3–5 respectively. Silver could be separated from 10‐fold molar excesses of copper, zinc and lead; uranium from 10‐fold molar excesses of gold and iron and 100‐fold molar excesses of sulphate and manganese: gold from a 10‐fold molar excess of uranium. Methods are suggested whereby redispersion in precipitate flotation of the second kind can be avoided. The efficiency of this kind of flotation is considered.