摘要:

Attempts were made to prepare sodium cyanide by Adamson's method. Yields of only 36–37% were obtained and explosions occurred frequently during the initial heating operation. An apparatus was designed and a procedure developed whereby the rate of the initial reaction could be controlled. Conditions of reaction are described under which no explosions have been encountered. The effects of fusion temperature and length of fusion time were studied. Maximum yields of 79.4–84.9% were obtained by fusing at approximately 630 °C. for 20 min.

ISSN:1923-4287    

DOI:10.1139/cjr50b-042

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The Darapsky method has been successfully applied to the synthesis of aminoacids from substituted cyanoacetic esters, RCH (CN)COOC2H5. R=CH3CH (CH2)4CH3, CH3CH(CH2)5CH3, CH3(CH2)11, HOCH2CH2,o-ClC6H4CH2,p-CH3C6H4O(CH2)2,p-CH3C6H4O(CH2)3,p-C2H5C6H4O(CH2)2,p-C2H5C6H4O(CH2)3,p-ClC6H4O(CH2)2,p-ClC6H4O(CH2)3,p-BrC6H4O(CH2)3. The esters were prepared by condensation of cyanoacetic ester with suitable bromides. When treated with hydrazine hydrate, they gave rise to hydrazides, which were identified by their anisal derivatives. Azides were obtained by the action of nitrous acid on hydrazides at low temperature and were transformed by heating with alcohol into carbethoxyaminonitriles. Finally, the latter by hydrolysis yielded the following amino acids:dl-α-amino-β-methylcaprylic acid,dl-α-amino-β-methylpelargonic acid,dl-α-aminomyristic acid,dl-α-amino-γ-hydroxybutyric acid,dl-α-amino-γ-p-methylphenoxybutyric acid,dl-α-amino-δ-p-methylphenoxyvaleric acid,dl-α-amino-γ-p-ethylphenoxybutyric acid,dl-α-amino-δ-p-ethylphenoxyvaleric acid,dl-α-amino-γ-p-chlorophenoxybutyric acid,dl-α-amino-δ-p-chlorophenoxyvaleric acid, anddl-α-amino-δ-p-bromophenoxyvaleric acid.

ISSN:1923-4287    

DOI:10.1139/cjr50b-043

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The kinetics of the polymerization of acetylene to cuprene on a copper catalyst between 200° and 300 °C. have been studied manometrically in a static system. The maximum velocity of the autocatalytic reaction shows a first-order dependence upon acetylene pressure. The reaction is retarded in the presence of small amounts of oxygen but accelerated by preoxidation of the catalyst. The apparent activation energy, of about 10 kcal. per mole for cuprene growth between 210° and 280 °C., changes to about 40 kcal. per mole above 280 °C. at which temperature a second reaction seems to set in. Hydrogen, carbon monoxide, or nitric oxide has no effect on the reaction velocity. Series of five successive seedings have been obtained with cuprene originally grown on cuprite, and show an effect of aging of the cuprene.

ISSN:1923-4287    

DOI:10.1139/cjr50b-044

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Whenn-butyl mercaptan is reacted in a one to one ratio with butadiene in an emulsion system containing persulphate, crotyln-butyl thioether is exclusively formed as the product of the initiation step. That is, no 1, 2 or 3, 4 addition was found for this step but only the 1, 4. Crotyln-butyl thioether and methylvinylcarbinyln-butyl thioether have both been synthesized and certain physical properties determined. It is concluded that in all free radical attacks upon butadiene, the terminal carbon is attacked. The resulting radical may or may not resonate between structures which yield 1, 4 addition and 1, 2 addition; for example, when a mercaptan radical attacks, the resonance is suppressed, but, when styryl or butadienyl radical attacks, the resonance results in the observed ratios of 1, 2, 1, 4 addition in polybutadiene and copolymers of butadiene and styrene. The nature of the products and the yield indicates that the overwhelming number of initiations are made by butyl mercaptan radicals and termination is almost exclusively made by mercaptan.

ISSN:1923-4287    

DOI:10.1139/cjr50b-045

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The areas of mechanically cleaned cadmium electrodes, measured by rate of build-up of hydrogen overvoltage, have been shown to decrease with time of immersion in air-free acid solutions. The relative rate of decrease did not depend upon acid concentration in excess of 10−2molar, nor upon passage of current or initial area, but exposure to air accelerated the decrease in area. The measured area was shown to depend upon the current used for the measurement, particularly with electrodes of large areas. Copper electrodes did not show the effects observed with cadmium. Cadmium polarization was shown to be linearly related to current, and independent of the measured area. This indicates that concentration polarization is operative in the deposition of cadmium.

ISSN:1923-4287    

DOI:10.1139/cjr50b-046

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The potentials determined for mechanically cleaned cadmium electrodes in air-free sulphuric acid electrolyte were less negative than those reported for deposited electrodes. Cleaning under air-free conditions did not remove this difference. It appears that the physical condition of the electrode surface affects the potential.

ISSN:1923-4287    

DOI:10.1139/cjr50b-047

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The reactions of methyl radicals, produced by the photochemical decomposition of dimethylmercury, with cyclopropane, ethylene oxide, methanol and dimethyl ether have been investigated between 100° and 250 °C. The following activation energies (kcal. mole−1) for the abstraction of hydrogen from the compounds by methyl radicals were found: cyclopropane, 10.2; ethylene oxide 9.6; methanol, 8.2; and dimethyl ether, 8.0. The probability factors have been shown to be about 10−4for all the compounds investigated.

ISSN:1923-4287    

DOI:10.1139/cjr50b-048

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Lupinus arboreusSims has been found to contain two main alkaloids,l-sparteine andd-lupanine together with a small quantity ofl-lupanine. There may be present a trace ofd-sparteine, but no other alkaloid could be detected.

ISSN:1923-4287    

DOI:10.1139/cjr50b-049

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The steady state obtained by Mesrobian and Tobolsky when toluene solutions, containing the same total weight concentration but varying proportions of styrene and polystyrene, were exposed to ultraviolet light at elevated temperatures was shown to depend upon the catalytic conditions. It was therefore concluded that this state does not represent a true thermal equilibrium between monomer and polymer. In the absence of monomer, polystyrene in toluene solution underwent chain scission on irradiation with ultraviolet light or treatment with benzoyl peroxide and air, even when the average chain length was less than that corresponding to the steady state. When monomer and polymer coexist in the presence of light or large quantities of oxidizing agents, a steady state arising from the polymerization of styrene and the simultaneous degradation of polystyrene appeared to be a transient phenomenon. Ultimately the monomer polymerizes and degradation becomes the dominant reaction. The experimental results indicated that a given mass of benzoyl peroxide or air brought about the scission of a definite number of linkages, resulting in a definite decrease in the relative viscosity. In the absence of oxidizing agents or light, polystyrene in toluene solution was remarkably stable at 100 °C.

ISSN:1923-4287    

DOI:10.1139/cjr50b-050

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

By polymerizing styrene in emulsion it was possible to synthesize polystyrenes of known number average molecular weight, the chain length distributions of which corresponded closely to the Kuhn–Schulz relationNy = N0py−1(1 − p)2. This enabled a relation between intrinsic viscosity and number average molecular weight to be established for polystyrenes with chain length distributions of this functional form. Assuming this form of chain length distribution to remain unaltered on degradation, it was possible to estimate the average number of scission points per structural unit from viscosimetric measurements. The extent of thermal scission of polystyrene after one week at 144 °C. was shown to be negligible while benzoyl peroxide caused appreciable chain scission at 80 °C. and 100 °C. The number of scission points estimated from viscosimetric measurements was directly proportional to the mass of benzoyl peroxide added to the system, and the scission appeared to be essentially random over the limited range investigated.

ISSN:1923-4287    

DOI:10.1139/cjr50b-051

出版商:NRC Research Press    

年代:1950

数据来源: NRC