摘要:

By treatment of α-piperidone with sulphuryl chloride,β,β′-dichloro-α-piperidone was obtained. It was hydrolyzed to α,α′-dichloro-δ-amino-n-valeric acid, which was simultaneously reduced and cyclized to DL-proline, by low pressure hydrogenation, using Raney nickel, in alkaline solution. All the intermediate compounds were identified and characterized. The over-all yield of DL-proline is 33% calculated from α-piperidone.α-Piperidone was hydrolyzed to δ-amino-n-valeric acid, and the δ-phenylureido-n-valeric and δ-phthalimido-n-valeric acids were prepared. Halogenation of δ-phthalimido-n-valeric acid gave excellent yields of the α-bromo and α-chloro acids. These acids were hydrolyzed to the α-halogenated-δ-aminoacids. On treatment with alkali, they gave DL-proline in 56% and 50% yields respectively, from α-piperidone.Halogenation of δ-phenylureido-n-valeric acid gave the dibromo and the dichloro acids, which ring-close immediately into derivatives of α-piperidone.The different behavior of δ-benzoylamino, δ-phthalimido, and δ-phenylureido derivatives ofn-valeric acid with halogens, or halogenating agents is noted.

ISSN:1923-4287    

DOI:10.1139/cjr50b-032

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

An improved method of preparing polymethylene, (CH2)n, by the decomposition of diazomethane is described. A new polymer, polyethylidene, (CH3∙CH)n, has been obtained from diazoethane by the same reaction. Diazomethane-d2is reported for the first time. A new deuterated polymer, (CD2)n, obtained by the decomposition of diazomethane-d2has been synthesize

ISSN:1923-4287    

DOI:10.1139/cjr50b-033

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Accurate and convenient analyses for ethylene oxide can be obtained using 1% periodic acid in dilute perchloric acid as reagent. The time required is less than an hour and the precision is about 0.1–0.2%.

ISSN:1923-4287    

DOI:10.1139/cjr50b-034

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The essential oil ofPicea marianahas been prepared and its major constituents separated by fractional distillation. Evidence for the presence of 15 constituents has been obtained, and santene, tricyclene,l-α-pinene,l-camphene,l-β-pinene, myrcene,d- Δ3-carene,dl-limonene, terpinolene,dl-camphor,l-borneol, andl-bornyl acetate have been identified with certainty.

ISSN:1923-4287    

DOI:10.1139/cjr50b-035

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

It has been found possible to spread almost any powder on a water surface in a layer one particle thick and to study its surface pressure – area relation by conventional film balance techniques. A special sprinkler was developed for placing the powder on the surface, and flotation agents were adsorbed on particles which do not normally float. Fine particles needed extended outgassing and drying before they were sufficiently deflocculated. Although all films collapsed more or less readily on compression it was possible to define a point in the compression curve which represented a rigid film. The thickness of this film was a definite fraction of the mean particle diameter, measured by microscopic methods, the fraction varying with ease of agglomeration and with the shape of the particles. This method can be used for measurement of mean particle size and it possesses certain advantages over existing methods for many purposes.

ISSN:1923-4287    

DOI:10.1139/cjr50b-036

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The apparent volume of water sorbed by a zinc chloride activated charcoal has been measured over the entire range of relative pressures, employing an apparatus especially designed to eliminate carry-over of water vapor into the sorption cell. The apparent volume has been found to be consistently greater over the entire sorption isotherm than the normal volume of an equal weight of liquid water, and it tends to be slightly higher on desorption than on adsorption. The results are in qualitative agreement with those of Wiig and Juhola and in marked disagreement with those of Morrison and McIntosh.

ISSN:1923-4287    

DOI:10.1139/cjr50b-037

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The viscosities in dilute toluene solution of fractions of polystyrene prepared at various temperatures and catalyst concentrations were found to conform to the relation ηsp/C = [η] + k′ [η]2, wherek′ = 0.38. When styrene was co-polymerized with quantities of divinyl benzene insufficient to cause gelation the viscosity–concentration relation changed, resulting in values ofk′ from 0.50 to 0.84. It was concluded that the polystyrene molecule is normally linear.

ISSN:1923-4287    

DOI:10.1139/cjr50b-038

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Stream potential, electro-osmotic, and permeability measurements were made on cotton pads in the presence of distilled water. Several sources of irreproducibility have been eliminated from the usual experimental methods of measuring the ζ-potential. Uniform packing of the pad has been shown to be important. The Briggs method of evaluating the "pore factor" by electrical conductivity measurements was found to be invalid. An alternative method of determining the factor is proposed, based on an assumed value for the pore orientation factor and an indirectly measured value of the swollen specific volume of the fibers. The latter can in principle be determined by measuring one of the electrokinetic functions or the permeability coefficient over a range of pad concentrations. When pads of different concentration were used, the stream potential, electro-osmotic, and permeability functions were found to vary erratically in the same manner, an effect which, it has been concluded, originates from lack of uniform packing of the pad. The electro-osmotic measurements were found to require a large correction for capillary electro-osmosis, a source of error which has been overlooked by other workers. The ratio of the ζ-potential calculated from electro-osmosis to that from the stream potential was greater than unity and increased with increase in pad concentration.

ISSN:1923-4287    

DOI:10.1139/cjr50b-039

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

A new technique of measuring the ζ-potential of cellulose fibers, in which stream current potential measurements are carried out over a range of solid concentrations on a single pad, is described. In employing the stream potential method it is necessary to measure the d-c. resistance of the pad, since a pronounced dispersion effect yields a-c. resistance values which are in considerable error. Reversible electrodes must therefore be used and since stream current measurements can then be carried out, this simpler method is preferred. Degrees of swelling calculated from the stream data are consistently higher than those calculated from permeability measurements. This discrepancy indicates a serious limitation of the conventional electrokinetic theory when applied to swollen cellulose. A model of the fiber–liquid interface, consisting of partially dissolved electrically charged cellulose chains accounting for the observed discrepancy, is discussed. If this model is applicable, the physical significance of the ζ-potential becomes extremely complex.

ISSN:1923-4287    

DOI:10.1139/cjr50b-040

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Sulphite cellulose, rayon cellulose, and silk fibers in the presence of 10−4 Npotassium chloride show a 20 to 25% decrease in electrical resistance between 0 and 100 c.p.s. An additional but smaller decrease occurs between 100 and 15,000 c.p.s. The systems also show a marked capacitive reactance. Reversal of the sign of the ζ-potential in sulphite fibers destroys the effect. Non-swelling fibers such as asbestos, glass, and acetate rayon, slightly swelling nylon, and moderately swelling wool show no comparable behavior. It is evident that the phenomenon is related to the swelling properties of the systems, but it cannot be concluded whether it is associated with the surface or the interior of the swollen fibers.

ISSN:1923-4287    

DOI:10.1139/cjr50b-041

出版商:NRC Research Press    

年代:1950

数据来源: NRC