摘要:

In an experimental carbon black plant of the channel type, the effect of channel height, draft control and gas composition on the properties of the carbon has been examined. The channel height was shown to be the most important variable. The rubber reinforcement and the yield of the carbon vary in a similar manner with the channel height at which the carbon was recovered. The sorption of the iodine and methylene blue increased almost logarithmically with the channel height. No direct relation between reinforcement and sorption is possible over the whole range, although the very high sorption obtained at greater channel heights was accompanied by a retarded cure. Sorption was increased by heating the blacks. The volatile content is high at low channel heights, passing through a minimum at the point of optimum yield. This test showed even poorer correlation with rubber reinforcement. Apparent density varied directly with channel height.The effect of draft control upon reinforcement, sorption, and volatile content was indefinite. However, the volatile content seemed to vary directly with the yield. No effects characteristic of the gas composition were found.

ISSN:1923-4287    

DOI:10.1139/cjr37b-021

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

The copper oxide catalyzed polymerization of acetylene to cuprene has been studied between 230° and 330 °C. by the flow method. The reaction shows an initial induction period at the lower temperatures followed by a rapid rise to a maximum rate and a more gradual decrease. With increase in temperature the induction period becomes shorter, and the maximum rate attained becomes greater. If commenced at 330 °C. the reaction is explosive. Analysis of the exit gas shows considerable ethylene and some free hydrogen, the amounts increasing with the temperature of the reaction. This indicates that the hydrogen split off in cuprene formation does not bear a constant ratio to the amount of cuprene formed. The yield of cuprene based on acetylene reacting is about 85% of theory, which is 4 to 10% lower than values based on a volume contraction of acetylene alone.An exponential equation has been derived which expresses the rate of absorption of acetylene at 290 °C. over a period of 72 hr. under the conditions of the experiment. The equation is integrated to give the quantity of acetylene absorbed at any time. This makes a prediction of yields possible. The heat of polymerization was calculated from the determined heat of combustion of cuprene. Various theories regarding the mechanism of formation and structure of cuprene are discussed, and the photochemical evidence of a chain reaction is supported.

ISSN:1923-4287    

DOI:10.1139/cjr37b-022

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

The specific heat of cellulose has been determined for the temperature range − 70° to 25 °C. The heat capacity of water sorbed to the extent of 5.92 and 12.0% by cellulose has been determined for the range − 78.5° to 25 °C. These data are compared with the heat capacity of pure water for the same range of temperature,viz., − 78.5° to 25 °C.

ISSN:1923-4287    

DOI:10.1139/cjr37b-023

出版商:NRC Research Press    

年代:1937

数据来源: NRC

摘要:

The homogeneous decomposition of methylene diacetate vapor to formaldehyde and acetic anhydride at temperatures between 220° and 305 °C. and at pressures ranging from several centimetres of mercury to several atmospheres has been studied. Reaction rates were determined by analytical and by pressure change methods. The first order decomposition is opposed by a second order recombination. A secondary reaction makes it impossible to determine the exact position of the resulting equilibrium. Within the rather large experimental error, methylene diacetate has the same activation energy (33,000 cal.) as its homologues. Its specific reaction velocity is smaller than that of the ethylidene esters. Methylene dipropionate and dibutyrate decompose at the same rate as the diacetate. These facts are in accord with the hypothesis that the extent to which a radical can contribute to the energy of activation is dependent upon its position in the molecule. Veolcity constants are given by the equation

ISSN:1923-4287    

DOI:10.1139/cjr37b-024

出版商:NRC Research Press    

年代:1937

数据来源: NRC