Effect of Temperature and Pressure on Oxygen Pressure Aging

1943 ◽  
Vol 16 (2) ◽  
pp. 453-465 ◽  
Author(s):  
A. M. Neal ◽  
H. G. Bimmerman ◽  
J. R. Vincent
Keyword(s):  
Temperature Coefficient ◽  
Oxygen Pressure ◽  
The State ◽  
Effect Of Temperature ◽  
Individual Study ◽  
Aging Rate ◽  
Temperature Coefficients ◽  
Pressure Test ◽  
Temperature And Pressure

Abstract An increase in the temperature of the oxygen pressure test from 70° to 80° C greatly increases the rate of aging of rubber vulcanizates. The temperature coefficients of aging rate for the six stocks tested vary between 1.63 and 3.48. The state of cure markedly affects the temperature coefficient of some stocks. It is obvious that no change in the specification from 70° to 80° C should be made without first determining the temperature coefficient of the stock involved. A decrease in the pressure of the oxygen pressure test decreases the rate of aging, but the rate is not proportional to pressure. The relative rates of aging between 0.5 and 300 pounds oxygen pressure for the stocks tested vary between 1.09 and 4.87 for the normal cures, and between 1.50 and 6.74 for the longer cures. The state of cure markedly affects the change in rate of aging with change in pressure. The data show that changes in the pressure of the oxygen pressure test must be accompanied by a revision of all aging specifications, which will involve an individual study of each stock and every cure of each stock, since no correlation between stocks seems to exist for the changes in rate of aging that occur with changes in pressure.

Soft Vulcanized Rubber. Effect of Temperature and Oxygen Pressure on Aging Rate

1937 ◽  
Vol 10 (2) ◽  
pp. 336-345
Author(s):  
J. H. Ingmanson ◽  
A. R. Kemp
Keyword(s):  
Oxygen Pressure ◽  
Mechanical Strain ◽  
Accelerated Aging ◽  
Effect Of Temperature ◽  
Aging Rate ◽  
Vulcanized Rubber ◽  
Rubber Compounds ◽  
Cause Of Failure ◽  
Service Conditions ◽  
Oxidation Effect

Abstract IMPORTANT to the manufacturer and consumer of rubber goods are suitable accelerated aging tests for predicting readily the life of rubber articles under the variable storage and service conditions encountered. Since service conditions may involve the exposure of rubber to wide variations of temperature, light, and atmosphere under various types of mechanical strain, there is obviously need for a variety of tests, each designed to emphasize factors which are most important in any given set of service conditions. Since the primary cause of failure of soft vulcanized rubber in service is oxidation, emphasis has been placed on tests which accelerate the oxidation effect. The most widely adopted and generally satisfactory procedure of this type is the Bierer and Davis oxygen bomb method which involves heating the rubber under oxygen pressure. In Bierer and Davis' original publication (2), results were shown on the effect of increasing oxygen pressure in increments of 28.1 kg. up to 112.5 kg. per cm. on the aging of two different rubber compounds at the three temperatures, 50°, 60°, and 70° C. Their results showed that in some cases there was a uniform increase in aging rate with increased pressure and in other cases the rate increased rapidly up to a pressure of 28.7 kg. per sq. cm. but more slowly with further increases in pressure. In a later investigation (3) the same authors employed a pressure of 21.1 kg. per sq. cm. and 60° C. throughout. For the past ten years most laboratories have used an oxygen pressure of 21.1 kg. per sq. cm. and a temperature of 70° C., which may therefore be considered as standard.

Temperature Coefficient of Vulcanization of Buna-S

1944 ◽  
Vol 17 (2) ◽  
pp. 412-420
Author(s):  
La Verne E. Cheyney ◽  
Robert W. Duncan
Keyword(s):  
Temperature Coefficient ◽  
Chemical Nature ◽  
The United States ◽  
Rate Of Change ◽  
Effect Of Temperature ◽  
Physical Test ◽  
Temperature Coefficients ◽  
Chemical Combination ◽  
General Range

Abstract Temperature coefficient of vulcanization may be defined as the increase in time of vulcanization necessary to produce a given property in the vulcanizate per unit range of temperature decrease, the latter being taken usually as either 10° F or 10° C. Coefficients of vulcanization for natural rubber stocks have been determined by several investigators. Although the data vary somewhat with the worker and with the stock investigated, the general range of temperature coefficients is close to 2.0 per 10° C. This is regarded as evidence of the chemical nature of the vulcanization reaction. The values obtained from physical test data do not always agree with those from combined sulfur analyses. This has been interpreted as an indication that the chemical reaction between the rubber and sulfur is not a simple bimolecular one, and that the rate of change of physical properties is not directly related to the rate of chemical combination of rubber and sulfur. A number of studies were published recently on the effect of variables on the vulcanization of Buna-S (now called GR-S in the United States) and on the properties of the resulting vulcanizates. In addition, compounding reports have been issued by manufacturers of rubber chemicals, as well as confidential reports submitted to the Rubber Director's office by rubber manufacturers. None of the published investigations, however, have been concerned with the determination of numerical relations among the properties of vulcanizates obtained at various temperatures. The properties of Buna-S vulcanizates differ markedly from those of rubber in certain characteristics, while possessing certain similarities in others. The only published mention of the effect of temperature on Buna-S stocks was in a release from the office of the Rubber Director, giving tables for conversion of cure to a standard temperature. These tables are based on a temperature coefficient of 1.43 per 10° F. The source of this information is not available, however.

Effect of Temperature and Pressure on Oxygen Pressure Aging

1942 ◽  
Vol 34 (11) ◽  
pp. 1352-1357 ◽  
Author(s):  
A. M. Neal ◽  
H. G. Bimmerman ◽  
J. R. Vincent
Keyword(s):  
Oxygen Pressure ◽  
Effect Of Temperature ◽  
Temperature And Pressure

Effect of temperature and pressure on mixed oxide solid solutions

2020 ◽  
Vol 117 ◽  
pp. 107965
Author(s):  
M.Yu. Petrushina ◽  
E.S. Dedova ◽  
K.V. Yusenko ◽  
A.S. Portnyagin ◽  
E.K. Papynov ◽  
...  
Keyword(s):  
Solid Solutions ◽  
Mixed Oxide ◽  
Effect Of Temperature ◽  
Temperature And Pressure

SOLUBILITY OF ETHYLENE IN WATER. EFFECT OF TEMPERATURE AND PRESSURE

1952 ◽  
Vol 44 (1) ◽  
pp. 211-212 ◽  
Author(s):  
E. J. Bradbury ◽  
Dorothy McNulty ◽  
R. I. Savage ◽  
E. E. McSweeney
Keyword(s):  
Effect Of Temperature ◽  
Water Effect ◽  
Temperature And Pressure

A STUDY OF THE MECHANISM AND KINETICS OF THE SULPHITE PROCESS

1939 ◽  
Vol 17b (4) ◽  
pp. 121-132 ◽  
Author(s):  
J. M. Calhoun ◽  
F. H. Yorston ◽  
O. Maass
Keyword(s):  
Temperature Coefficient ◽  
Arrhenius Equation ◽  
Practical Interest ◽  
Effect Of Temperature ◽  
Wood Meal ◽  
Spruce Wood ◽  
Mechanism And Kinetics ◽  
Kinetics Of

The rate of delignification of resin extracted spruce wood-meal has been determined in calcium-base sulphite liquor at temperatures from 130 °C. down to 50 °C. No break was found in the temperature coefficient curve at the lower temperatures, the reaction following the Arrhenius equation closely. Possible mechanisms of the reaction are discussed in the light of existing theories, and the effect of temperature on the yield of pulp is pointed out for its practical interest.

The Effect of Temperature and Pressure on Residual Stress in LPCVD Polysilicon Films

1992 ◽  
Vol 276 ◽  
Author(s):  
D-G. Oei ◽  
S. L. McCarthy
Keyword(s):  
Residual Stress ◽  
Deposition Temperature ◽  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Effect Of Temperature ◽  
Pressure Chemical ◽  
Polysilicon Films ◽  
Oriented Polycrystalline ◽  
Temperature And Pressure ◽  
Reduced Pressures

ABSTRACTMeasurements of the residual stress in polysilicon films made by Low Pressure Chemical Vapor Deposition (LPCVD) at different deposition pressures and temperatures are reported. The stress behavior of phosphorus (P)-ion implanted/annealed polysilicon films is also reported. Within the temperature range of deposition, 580 °C to 650 °C, the stress vs deposition temperature plot exhibits a transition region in which the stress of the film changes from highly compressive to highly tensile and back to highly compressive as the deposition temperature increases. This behavior was observed in films that were made by the LPCVD process at reduced pressures of 210 and 320 mTORR. At deposition temperatures below 590 °C the deposit is predominantly amorphous, and the film is highly compressive; at temperatures above 610 °C (110) oriented polycrystalline silicon is formed exhibiting high compressive residual stress.

Synergetic effect of temperature and pressure on energetic and structural characteristics of {ZIF-8 + water} molecular spring

Nanoscale ◽  
2015 ◽  
Vol 7 (19) ◽  
pp. 8803-8810 ◽  
Author(s):  
Ya. Grosu ◽  
G. Renaudin ◽  
V. Eroshenko ◽  
J.-M. Nedelec ◽  
J.-P. E. Grolier
Keyword(s):  
Structural Characteristics ◽  
Synergetic Effect ◽  
Effect Of Temperature ◽  
Temperature And Pressure
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