摘要:

To evaluate the effect of drying temperature on the composition of high molecular weight ligninsulphonic acids, samples of a dialyzed ligninsulphonic acid solution were dried in several ways. Analyses showed that heating the solution to 70 °C for 16 hr. did not give an anhydrous material. When this material was heated for an additional period of 22 hr. at 90 °C, it became anhydrous and also lost part of its sulphur content. Air drying of either the free acid or the calcium salt, followed by grinding and dryinginvacuoto constant weight, produced materials with essentially the same elemental composition after allowance was made for the calcium content, and because of this it is concluded that no decomposition of the free acid occurred during this drying process. Elementary analyses were in good agreement with those reported by other workers. The hydroxyl content found for the free acid was lower, and the oxygen content was higher, than the corresponding values reported by Erdtman, Lindgren, and Pettersson or those reported by Freudenberg, Lautsch, and Piazolo.

ISSN:0008-4042    

DOI:10.1139/v54-139

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

The specific and equivalent conductances (which also involve thedensities) of aqueous solutions of silver nitrate and of ammonium nitrate, ranging in concentration from 0.1 Mto that of the pure molten salt, have been determined at temperatures of 221.7 °C and 180.0 °C, respectively. It has been found that when the equivalent conductance is plotted against logarithm of the concentration, a straight line is obtained in the region of concentrations greater than about 6 Mor less. Hence the equivalent conductance can be calculated from the relationwhereD = the slope and Λa = equivalent conductance at the limiting experimental concentration,Ca(in the molten state).

ISSN:0008-4042    

DOI:10.1139/v54-140

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

The photolysis of 2,2′-azo-bis-isobutyronitrile (AIN) has been studied in benzene solution through combined Corning filters 9863 and 5850 in the near ultraviolet, employing a General Electric UA-2B quartz Uviarc as a light source. An over-all quantum yield of 0.43 was found. The rate of decomposition of AIN in moles/liter seconds for this system is equal to 0.43 × [total light absorbed]. Twice this value may be taken as the rate of initiation when AIN is used as a photochemical initiator of polymerization.

ISSN:0008-4042    

DOI:10.1139/v54-141

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

The thermal decomposition in a vacuum at 100 °C of both whole and ground crystals of pure dry silver permanganate was followed by the measurements of increase in pressure and of loss in weight. The decomposition products were determined by analysis and calculations to be silver oxide, silver, manganese dioxide, silver permanganite, and oxygen. On the basis of chemical analysis the following mechanism of decomposition is proposed:(1)(2)(3)The reaction proposed in equation (1) goes to completion, while the reaction proposed in equation (2) goes to approximately 37.7% completion, and that in equation (3) goes to approximately 6.6% completion.

ISSN:0008-4042    

DOI:10.1139/v54-142

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

This study elucidates the details of a typical initiation encountered in polymerization. A kinetic mechanism for the photoinitiated addition of normal butyl mercaptan to single and conjugated double bonds is proposed, and the corresponding velocity constants namely the attackkα, the transferkct, and the terminationkthave been measured employing a sector method. For the concentrations employed in this work the over-all rate of addition to the double bond is determined by the transfer rate of the composite mercapto monomer radical, while the capture of initiating radicals depends on the rate of attack of the mercaptyl radicals on the double bonds. The transfer rate is about 1000 times faster for a pentenyl than for a conjugated styryl radical, while the attack step is estimated to be several hundred times faster for the conjugated monomer. These conclusions are shown to be consistent with results observed when conjugated and unconjugated monomers are in competition, and are in agreement with the quantum mechanical structure of the radicals and molecules involved. This work reports a general survey of the field, and subsequent papers will extend the observations.

ISSN:0008-4042    

DOI:10.1139/v54-143

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

Light-scattering measurements of bovine serum albumin made at pH 1.9 in 0.1 M-0.45 Mpotassium chloride show that the molecule is not dissociated, but has the same molecular weight as in neutral solution. At pH 1.9 in the absence of salt aggregation occurs, the extent increasing with time. The sedimentation constant at pH 1.9 increases from 3.2S in 0.1 Mpotassium chloride to 3.6 in the 0.5 Msalt, compared with 4.3 in neutral solution. These differences are ascribed to changes of molecular shape.

ISSN:0008-4042    

DOI:10.1139/v54-144

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

The formation of sodium triphosphate by calcination, below the sodium triphosphate fusion point, of various phosphate mixtures of over-all composition 5Na2O.3P2O5.xH2O was investigated. Water plays an important role, decreasing the amounts of pyrophosphate and high molecular weight polyphosphate impurities and increasing the reaction rate under certain conditions. It is suggested that water catalyzes the reactions by: (1) facilitating ionic diffusion, (2) hydrolyzing —P—O—P—linkages, and (3) assisting in the crystallization of sodium triphosphate. With ortho- and pyro-phosphate mixtures temperatures of about 300 °C. and higher are necessary for the rapid formation of sodium triphosphate. With glasses of the composition 5Na2O.3P2O5good yields may be obtained at temperatures as low as 250 °C. when water is present.

ISSN:0008-4042    

DOI:10.1139/v54-145

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

A procedure is described for the accurate analysis of ethylene in mixtures of ethane and ethylene by hydrogenation over a nickel–kieselguhr catalyst. Samples of ethylene as small as 0.03 cc. in mixtures of the order of 1.5 cc. of gas at N.T.P. can be determined to an accuracy of about one half per cent. Results are reported over a range of mixtures.

ISSN:0008-4042    

DOI:10.1139/v54-146

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

Ornithine-2-C14was fed to matureDaturastramoniumplants and radioactive hyoscyamine was isolated from the whole plant, while the hyoscine obtained from the plant was inactive. Systematic degradation of the radioactive alkaloid indicated that all the activity was present in the 1 or 5, or both, positions of the tropine half of the alkaloid indicating that ornithine is a precursor of the ring system in tropine, but not of scopine, the base present in hyoscine.

ISSN:0008-4042    

DOI:10.1139/v54-147

出版商:NRC Research Press    

年代:1954

数据来源: NRC

摘要:

The standard intensities of the Raman bands of the chloroethanes without rotational isomers (Et; 1,1; 1,1,1; 1,1,1,2; penta, and hexa) have been measured in the liquid phase with a photoelectrically recording Raman spectrometer. Vibrational assignments are proposed which are consistent with the depolarization data, infrared contours, and a vibrational sum rule. The total Raman intensity is a smooth but nonlinear function of the number of chlorine atoms. The sum of the intensities of the bands assigned to hydrogen modes and that for the skeletal modes is also a smooth function of the number of substituents.

ISSN:0008-4042    

DOI:10.1139/v54-148

出版商:NRC Research Press    

年代:1954

数据来源: NRC