bluuebunny/crossref_metadata_2025_split huggingface dataset:
Azeotropic distillation apparatus
Authors: Raper D. 
Published: July 2010

AbstractThe paper describes an apparatus embodying, in a single unit which can be assembled in a few minutes, all the components necessary to condense, separate automatically and return the solvent and take off the water in azeotropic distillations.The apparatus is suitable for reactions on any reasonable scale using various solvents lighter or heavier than water. Difficulty has been experienced with benzene, but means are suggested for overcoming it.
Film resistances in rectification
Authors: Chari K. S. , Storrow J. Anderson 
Published: July 2010

AbstractAttempts have been made to analyse data from rectification in a wetted‐wall column in terms of postulated equations for film values of the height of a transfer unit (HTU) values. Discrepancies found in some of the correlations are no greater than are to be expected from our lack of knowledge of physical characteristics of the binary mixtures, notably of the diffusion coefficient in the liquid phase.
P‐aminobenzenesulphonylphenylcyanamide (N4‐cyano‐sulphanilide) and related compounds
Authors: Kurzer F. 
Published: July 2010

AbstractExtension of the general method for the preparation of sulphonylcyanamides by the interaction of arylureas and aromatic sulphonyl chlorides has given p‐aminobenzenesulphonylphenylcyanamide by two routes. A number of related substituted sulphonamides of this type are also described. Migliardi and Tappi's claim to have obtained sulphonylureas from as‐diarylurea and arylsulphonyl chlorides could not be substantiated, the expected diarylcyanamides being obtained instead under the conditions of the present synthesis.Attempts to extend to arylsulphonylarylcyanamides the general reaction of converting cyanamides to thioureas by the addition of hydrogen sulphide were unsuccessful.
The use of ethyl silicate in providing heat‐resistant coatings of aluminium on steel
Authors: Tolley G. 
Published: July 2010

AbstractThe doping of sprayed aluminium with ethyl silicate has been found to give a heat‐resistant coating which needs no heat treatment before putting into service. This coating is compared with aluminizing, and the relative protection given by these two coatings to mild steel from 700° to 950° C. has been determined.
The analytical examination of plasticizers obtained from polyvinyl chloride compositions
Authors: Haslam J. , Soppet W. , Willis H. A. 
Published: July 2010

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 mixtures.
Sulphonated cross‐linked polystyrene: A monofunctional cation‐exchange resin
Authors: Pepper K. W. 
Published: July 2010

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 ions are indicated.
A method for the quantitative estimation of copper with particular reference to proofed jute fabrics
Authors: Macmillan W. G. , Das P. C. 
Published: July 2010

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.
Design of packed distillation columns. IV. An empirical method for the estimation of column height using the H.E.T.P. concept
Authors: Hands C. H. G. , Whitt F. R. 
Published: July 2010

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 viscosity.
Formaldehyde condensations with phenol and its homologues. XI. The preparation of 2‐hydroxymethyl‐3:5‐dimethylphenol by a new general method
Authors: Finn S. R. , Musty J. W. G. 
Published: July 2010

AbstractIn Part V of this series, it was shown that the reaction of formaldehyde with 3:5‐dimethylphenol could result in the formation of either the p‐monoalcohol or the 0‐0′‐dialcohol, according to the reaction conditions.The 0‐monoalcohol (2‐hydroxymethyl‐3:5‐dimethylphenol) has now been prepared from 2‐dimethylaminomethyl‐3:5‐dimethylphenol by conversion with acetic anhydride to 1‐acetoxy‐2‐acetoxy‐methyl‐3:5‐dimethylbenzene, followed by reduction of the latter with lithium aluminium hydride. This process may be expected to provide a general method for the preparation of phenolic alcohols from the parent phenols.The structure of the 0‐alcohol has been confirmed by reduction of the corresponding aldehyde with lithium aluminium hydride.
Synthesis of molecular units for rational synthesis of phenol‐formaldehyde and allied resins. I. Synthesis of resoles, dihydroxydiphenylethanes, and dihydroxydiphenylpropanes
Authors: Carpenter A. T. , Hunter R. F. 
Published: July 2010

AbstractThe rational synthesis of polycondensation individuals produced during the formation of phenol‐formaldehyde and allied resins by reactions leading to unequivocal structures has been begun. Three resole structures have been synthesized by methods which offer extension to other intermediates : (i) 2 : 4′‐Dihydroxy‐5‐hydroxymethyldiphenylmethane was synthesized by application of a lithium‐exchange reaction with n‐butyl‐lithium to 5‐bromo‐2 : 4′‐dihydroxydiphenylmethane by way of the 5‐carboxy‐2 :4′‐dihydroxy‐derivative which was reduced to the required compound by lithium aluminium hydride; (ii) 2 : 2′‐dihydroxy‐3 : 5‐bishydroxymethyldiphenylmethane was synthesized from 3 : 5‐dibromo‐2 : 2′‐dihydroxydiphenylmethane by way of 3 : 5‐dibromo‐2 : 2′‐dihydroxy‐3′: 5′‐bishydroxymethyldiphenylmethane, which on controlled reduction with palladium‐hydrogen furnished the required bishydroxymethyl compound; (iii) 2:4: 6‐trishydroxymethylphenol was obtained by reduction of ethyl hydroxytrimesate by lithium aluminium hydride in dioxan.As a contribution towards the problem of ‘ cross‐linking ’ in phenolic resins, I : 2‐di‐(p‐hydroxy‐phenyl)ethane, I: 2‐di‐(o‐hydroxyphenyl)ethane, and I‐o‐hydroxyphenyl‐2‐p‐hydroxyphenylethane, in which the phenolic nuclei are separated by an additional methylene group, have been rationally synthesized with a view to comparison of their reaction with formaldehyde with that of the corresponding dihydroxydiphenylmethanes. The corresponding isomeric dihydroxydiphenylpropanes have also been prepared for investigation of the effect of insertion of a further methylene group between the phenolic nuclei.
The kinetics of continuous reaction processes: Application to polymerization
Authors: Denbigh K. G. 
Published: July 2010

AbstractThe paper discusses the general principles of the kinetics of reactions as carried out in the two main types of continuous process. Comparison is made with the corresponding batch system with regard to the necessary volume of reaction space. It is shown that a correct choice of the type of process can sometimes be used to increase the yield of a reaction. The application of these principles to polymerization is described in outline.
The chemistry of phenolic resins and the processes leading to their formation
Authors: Zinke Alois 
Published: July 2010

AbstractThe paper presents first a review of the work on phenolic resins done by Euler and his co‐workers, by Hultzsch and by Zinke and his team, and of the importance of this work for the knowledge of the hardening process. More recent research work of Zinke and his co‐workers, especially on cyclic polynuclear phenols is also described. There is a short discussion of the chemistry of novolaks and of the work of Ziegler. Results of research on the hexamine‐hardening process are also discussed.
Recent developments in x‐ray diffraction studies of high polymers
Authors: Bunn C. W. 
Published: July 2010

AbstractExamples of preferred ‘tilted crystal’ orientations in fibres during the early stages of drawing and also during contraction on heating are described. The crystallographic direction of tilt in drawing is, in the examples studied so far, not the same as the direction of tilt in relaxation. Tilted‐crystal X‐ray diffraction patterns give very valuable aid in the determination of the crystal structures of high polymers.The ability of high polymers to crystallize depends on geometrical regularity of molecular structure; chemical or stereochemical irregularity prevents crystallization unless the alternative groups of atoms are similar in size and shape.The determination of the proportions of crystalline and amorphous material in polymer specimens by the X‐ray diffraction method is discussed. The experimental requirements and the underlying theoretical assumptions are pointed out.A reversible transition of a novel type has been detected in polytetrafluoroethylene: the onset of partial disorder in the crystals at room temperature, 300° c. below the melting point.
Practice of osmometry: Its contribution to the characterization of a high polymer
Authors: Cleverdon D. 
Published: July 2010

AbstractOsmometers are reviewed, together with the current opinion concerning thermodynamic investigations arising from their use. The validity of osmotic pressures extrapolated to infinite dilution to provide one of the fundamental molecular weight averages is emphasized. The nature of distribution curves constructed from a single type of molecular weight average is discussed. The number‐average and viscosity‐average distribution curves of a commercial polystyrene are compared. The number‐average molecular weights are also used to compare the Beall procedure of treating fractionation data with the classical one. The Beall procedure indicates the presence of a very high molecular weight ‘tail’ to the distribution, for whose existence there is ancillary evidence.
Studies on birefringence of macromolecular solutions
Authors: Sadron C. 
Published: July 2010

AbstractA large amount of work has been done during recent years in order to find out the main properties of submicroscopic particles dispersed in a liquid from the mean physical properties of their solutions, such as viscosity, light‐scattering power, osmotic pressure, and Brownian diffusion.In general it is necessary to study several of these properties before predicting mass, shape, dimensions, mechanical or optical characters of the particles.This paper gives a brief survey of the results that may be obtained from the study of the double refraction which can be induced in a macromolecular solution by application of a proper field of orientation, namely a hydrodynamical or an electrical field. The effect of a magnetic or of an ultrasonic field is not discussed in this paper because of the uncertainty of the interpretation of the experimental results so far obtained.The case of a hydrodynamical field (stream double‐refraction) has actually been previously studied more thoroughly; it is considered in this paper, but some results obtained in the second case (Kerr effect), which seem to be very promising, will also be given.
Mechanism of the degradation of polyamides
Authors: Achhammer Bernard G. , Reinhart Frank W. , Kline Gordon M. 
Published: July 2010

AbstractFilms of polyamides were exposed to heat, ultra‐violet radiant energy, and different atmospheric conditions. The degradation products were collected in some cases and analysed by mass‐spectrometric techniques. The unexposed and exposed specimens were examined by the following techniques to obtain information concerning the changes in chemical and physical structure of the polymer: infra‐red absorption, ultra‐violet absorption, viscosity of solutions, measurement of dielectric constant and dissipation factor, photomicrography, X‐ray diffraction, electron microscopy, and effect of organic liquids. In addition, pyrolysis studies were made and some physical properties were determined. The results of the investigation show clearly that no single method gives a complete picture but that the results from several of the methods give an insight into the degradation mechanism. The general course of the degradation of polyamides may be described as follows : (I) splitting of the polymer chain at the C‐N linkages; (2) changes in degree of crystallinity or local order; and (3) loss of dipole‐associated plasticizers.
Corrosion experiments with gaseous boron trifluoride
Authors: Hudswell F. , Nairn J. S. , Wilkinson K. L. 
Published: July 2010

AbstractA number of constructional materials—metals, alloys and miscellaneous compounds—which may be required to come into contact with boron trifluoride were subjected to treatment with this gas under carefully controlled conditions.The materials were examined by bringing into contact with gas at an original fixed pressure of about 25 cm. of mercury, and at temperatures up to 200° c. The extent of the reaction, if any, was shown by the alteration of the gas pressure over the sample.Many of the materials examined showed a high resistance to chemical attack by boron trifluoride. The following materials can be safely used in apparatus for handling dry boron trifluoride : stainless steel, mild steel, copper, nickel, Monel metal, brass and aluminium, the more noble metals up to at least 200° c.; Pyrex glass is also suitable up to about 200° c.; Araldite cement, fired pyrophyllite and polytetrafluoroethylene may be used up to 80° c. Great variation was shown by the others in the miscellaneous group of compounds.
Some factors affecting the useful rates of reaction in the industrial polymerization of styrene
Authors: Elly Joyce , Haward R. N. , Simpson W. 
Published: July 2010

AbstractThe current values for the velocity constants for styrene polymerization are used to calculate the rates at which polystyrenes of particular viscosities can be prepared. It is shown that optimum temperatures should exist where there is the highest rate of formation of a polymer of specified viscosity. However, these rates can be exceeded in the later stages of bulk polymerization or in emulsion polymerization where the bimolecular termination reaction is restricted by a high‐viscosity medium or by compartmentalization. On the other hand, reduction‐activated bulk systems fall into line with the general theory proposed.
Polyethylene‐structure, crystallinity and properties
Authors: Richards R. B. 
Published: July 2010

AbstractBy polymerizing ethylene under various conditions of temperature and pressure a wide range of polymers may be made including oils, greases, soft and hard waxes and plastics both softer and harder than the familiar type of polymer used for electrical insulation and film. Some of these variations in properties are caused by changes in average molecular weight. Variations among samples of the same molecular weight are, however, observed; these cannot normally be attributed to changes in distribution of molecular weight but are due to differences in the structure of the polymer molecule. Many of the properties of the solid polymer are determined by the degree of crystallinity. This is affected little by average molecular weight and distribution of molecular weights, but is dependent to a major extent by the degree of chain branching. The measurement of chain branching and its effect on crystallization is discussed and the influence of average molecular weight and molecular structure on a number of properties, including cracking in organic liquids, is described. The importance of the arrangement of the crystalline regions is stressed.
Catalytic hydrogenation of 3:4‐epoxido‐4‐methyl‐2‐pentanone
Authors: Bergmann Ernst D. 
Published: July 2010

AbstractCatalytic hydrogenation of 3:4‐epoxido‐4‐methyl‐2‐pentanone with Raney nickel in isopropanol attacks the epoxide ring before the carbonyI group: The two isomeric forms of 4‐methylpentane‐2 : 3‐diol have been obtained together with methyI isobutyI ketone, a product of the combined hydrogenation and hydrogenolysis of the starting material.
The influence of carbon smokes on the dew‐point and sulphur trioxide content of flame gases
Authors: Whittingham G. 
Published: July 2010

AbstractDew‐point and chemical methods of analysis have been used to investigate the effect o carbon smokes on the sulphur trioxide content of flame gases. As the quantity of smoke increases from zero the conductivity‐temperature characteristics of condensed films of acid become complex owing to the deposition of electrically conducting carbon on the dew‐point element. Conductivity measurements indicate that deposited carbon and sulphuric acid films react at temperatures above about 140° c. Analytical determinations show that the sulphur trioxide content of the gases is decreased in the presence of carbon. Suggestions are made of the means whereby the sulphur trioxide content is lowered.
A mechanical foam‐generator for use in laboratories
Authors: Fry J. F. , French R. J. 
Published: July 2010

AbstractA description is given of the development and performance of a variable foam‐generator for use in laboratory experiments with mechanical foams for fire‐fighting.The generator is designed to provide accurate control of the character of the foam as measured by its expansion factor and its ultimate shear strength.The apparatus has been called a mechanical foam‐generator to distinguish it from equipment in which the disperse phase of the foam is generated chemically; air is the gas most commonly used for the disperse phase, but other gases may be used if required.
A laboratory method of comparing the efficiencies of fire‐fighting air‐foams
Authors: Fry J. F. , French R. J. 
Published: July 2010

AbstractA description is given of apparatus for comparing the efficiencies of different, mechanically‐produced, fire‐fighting foams by measuring a ‘figure of merit.’ The figure of merit used is a dimensionless index intended to take into account the ability of the foam to flow over the surface of an inflammable liquid, its resistance to destruction by contact with the liquid and its resistance to destruction by fire. Examination of the foam is carried out under standard conditions and the figure of merit is then defined as the ratio between the rate of coverage of the liquid surface by the foam and the rate of destruction of the foam when the liquid is allowed to burn.Figures of merit have been obtained for a number of different fire‐fighting foams on petrol.
Determination of the particle size of fine powders, with particular reference to kaolins
Authors: Rossi Corrado , Baldacci Ruffo 
Published: July 2010

AbstractThe sedimentation curves for suspension of kaolins from Central Europe, Italian bentonites and clays have been obtained by using a hydrostatic balance provided with a normal plunger. Investigations undertaken to establish the accuracy of the method and the theoretical calculation of the sedimentation curves are briefly described. The possibility of applying Stokes' law to the mass settling of kaolins is also discussed. The authors wish to emphasize (a) the possibility of determining the average diameter of powder particles by means of the tangent to the curve at zero time, and (b) the possibility of deducing from experimental sedimentation curves both the curves relating to size distribution (the number of particles as a function of equivalent diameter) and the cumulative curves (the percentage by weight of particles having dimensions smaller than one determined equivalent diameter).When carrying out sedimentation measurements, particularly with kaolins, it is possible to obtain regular curves only when conditions are such as to avoid flocculation. This result is achieved by adding suitable electrolytes in quantities which determine the smallest sedimentation volume.The average equivalent diameters of the powders examined were deduced from such sedimentation curves.Statistical measurements of dimensions made by direct microscopic observations have been carried out on two kaolins from Central Europe, resulting in average values which agree very closely with those calculated from the sedimentation curves.Cumulative curves of the usual type have been obtained from the densimetric curves of sedimentation.
The transmission of light through suspensions
Authors: Lothian G. F. , Chappel F. P. 
Published: July 2010

AbstractMeasurement of the optical transmission of a suspension of small particles is of considerable importance, e.g. for determination of particle size. In certain conditions interpretation of measurements is simple, i.e. when it may be assumed that the particles behave as an opaque screen of area equal to the total projected area of the particles in the beam. In general, however, the projected area must be multiplied by a factor K, known as the total scattering coefficient, which can have values between o and about 5.The present paper reviews the values of K as a function of the wavelength λ of the incident light, the refractive index, absorption and radius (a) of the particles, and the angular size of the detector used in an experimental arrangement.Attention is confined to spherical particles. By using elementary diffraction theory it is possible to obtain a physical picture of the reasons for the variation of K from the value I expected from geometrical optics. Exact methods of calculation are discussed, following Airy, Mie and Rayleigh for the respective cases a≫λ, a∽λ, a≪; some typical results from published calculations are quoted and reviewed, and optimum conditions for measurement are suggested.
ACenaphthylene: Its polymers and copolymers
Authors: Kaufman M. , Fowler Williams A. 
Published: July 2010

AbstractDetails of the laboratory and semi‐technical‐scale preparation of acenapththylene by the vapour‐phase dehydrogenation of acenaphthene are given.Polymerization of acenaphthylene is discussed together with some of the properties of the plasticized polymer. Copolymers with styrene have been studied in their preparation by bulk, bead and emulsion processes and some of their properties have been related to composition and mode of polymerization. The availability and economics of the monomer are considered briefly.