Carboxylic Rubbers. II. Properties of Cured Stocks

1959 ◽  
Vol 32 (1) ◽  
pp. 328-336 ◽  
Author(s):  
B. A. Dolgoplosk ◽  
V. N. Reĭkh ◽  
E. I. Tinyakova ◽  
A. E. Kalaus ◽  
Z. A. Koryushenko ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Elastic Properties ◽  
Good Resistance ◽  
Synthetic Rubber ◽  
Rubber Compounds ◽  
Resistance To Heat

Abstract The experimental evidence shows that the mechanical and elastic properties of the carboxylic rubber compounds far exceed those of the synthetic rubber type compounds. Important qualities of gum and lightly filled carboxylic rubber compounds are: good mechanical and elastic properties, high cut growth resistance and good resistance to heat aging. The disadvantage is the tendency of the carboxylic rubber mixtures to scorch. Carboxylic rubbers are of considerable interest for the preparation of general and special purpose rubber compounds.

Carboxylic Rubbers. I. Synthesis and Structures

1959 ◽  
Vol 32 (1) ◽  
pp. 321-327 ◽  
Author(s):  
B. A. Dolgoplosk ◽  
E. I. Tinyakova ◽  
V. N. Reĭkh ◽  
T. G. Zhuravleva ◽  
G. P. Belonovskaya
Keyword(s):  
Polymer Chain ◽  
High Strength ◽  
Chemical Compounds ◽  
Good Resistance ◽  
Synthetic Rubber ◽  
Rubber Compounds ◽  
Work Done ◽  
Styrene Butadiene ◽  
Resistance To Heat ◽  
Butadiene Styrene

Abstract It is well known that the high strength of unfilled (pure gum) natural rubber and some synthetic rubber compounds can be explained by the homogeneity of the polymer chain which determines its ability to crystallize or to orient on stretching. The character of the vulcanization network as well as the structure of the main chain is of importance. This has been verified by the use of polyethylene polyamines and other chemical compounds as vulcanization accelerators for butadiene-styrene rubber (SKS-30A) to produce high strength (up to 200 kg/cm2) gum rubber compounds. In certain cases, only the structure of the vulcanization network obtained with carboxyl-containing rubber compounds can account for obtaining the same effects as are obtained with natural or other synthetic rubber compounds as a result of homogeneity of polymer chain. The first work done by us on carboxyl-containing (carboxylic) rubbers was done in 1954\2-1955. In this work it was shown that polymers of isoprene and of butadiene, copolymers of butadiene with styrene, butadiene with acrylonitrile, and others, which contain small quantities of methacrylic acid (1\2-2 mole %) in the chain, can be vulcanized with oxides of divalent metals to give pure gum and lightly filled compounds characterized by high strength and elasticity, good resistance to heat aging and good cut growth resistance.

Crosslinking Chlorosulfonated Polyethylenes

1963 ◽  
Vol 36 (4) ◽  
pp. 963-974 ◽  
Author(s):  
J. T. Maynard ◽  
P. R. Johnson
Keyword(s):  
Free Radical ◽  
Sulfonyl Chloride ◽  
High Reactivity ◽  
Good Resistance ◽  
Chlorosulfonated Polyethylene ◽  
Ionic Salt ◽  
Ionic Bonds ◽  
Resistance To Heat ◽  
Curing Systems

Abstract The broadening practical use of chlorosulfonated polyethylene elastomers for applications where good resistance to heat, oil, light, oxygen, and ozone is needed has been accelerated by the development of several chemically distinct curing systems. Optimum use of these saturated elastomers requires a knowledge of the chemistry of these curing reactions and the effect of the resulting crosslink structures on vulcanizate properties. The high reactivity of the sulfonyl chloride crosslinking sites allows wide latitude in choice of curing chemistry, and crosslink type can be controlled to give a preponderance of ionic salt bonds or to give a mixture of covalent and ionic bonds. The role of water, alcohols, sulfur accelerators and free radical stabilizers in the various practical curing systems is discussed. The development of wholly organic curing systems for chlorosulfonated polyethylenes is reviewed. The properties of vulcanizates of chlorosulfonated polyethylenes are also significantly controlled by the base polyethylene, by chlorine content, and by chlorine distribution. The effects of these variables on vulcanizate properties is briefly reviewed.

High-Temperature Oven Aging of Oil-Resisting Synthetic Rubber Compounds

1945 ◽  
Vol 18 (3) ◽  
pp. 667-678
Author(s):  
G. D. McCarthy ◽  
A. E. Juve ◽  
H. Boxser ◽  
M. Sanger ◽  
S. R. Doner ◽  
...  
Keyword(s):  
High Temperature ◽  
Constant Temperature ◽  
Test Tube ◽  
Principal Factor ◽  
Synthetic Rubber ◽  
Rubber Compounds ◽  
Exposure Temperature ◽  
Hardness Change ◽  
Temperature Exposure ◽  
Good Heat

Abstract An investigation of the effect of varying conditions of high-temperature exposure has shown that, at a constant temperature, the supply of oxygen is the principal factor which causes stiffening of the vulcanizates. The loss of volatile plasticizers, when present, also contributes to the stiffening. The test-tube technique, developed in the course of this investigation, in which dumbbell samples are suspended in stoppered test-tubes (38 by 300-mm.) heated by immersion in an oil bath, appears to give results which are considerably more duplicable than those obtained by the usual aging in circulating air ovens. The test-tube technique also gives somewhat better differentiation between good-heat aging and poor-heat aging compounds. The rate of deterioration as measured by elongation change is doubled for an 18° F increase in the exposure temperature. As measured by hardness change the rate is doubled by an increase of 42° F. Tests run at 250° F by this method are no more reproducible than those run at 300° F.

The Impact Resiliometer

1934 ◽  
Vol 7 (3) ◽  
pp. 591-598 ◽  
Author(s):  
Paul Lüpke
Keyword(s):  
Elastic Properties ◽  
Physical Science ◽  
Sustained Load ◽  
Plastic Properties ◽  
Dual Nature ◽  
Hardness Tester ◽  
Vulcanized Rubber ◽  
Rubber Compounds ◽  
The Impact ◽  
Average User

Abstract Original Purpose The writer's first conception of an instrument for quickly measuring the resilience of rubber samples arose in connection with the basic idea for and development of the present A.S.T.M. hardness tester, in an endeavor to provide a reproducible means of measuring and expressing those properties of rubber compounds superficially apparent to the average user. It seemed that if the resistance to pressure (indenting or flexing) and the pressure, or force, of recovery, of a sample were duplicated, the article produced would “feel” the same as the sample, and under normal conditions of use would act mechanically the same. Nature of Problem This problem of measurement, as is generally known, is complicated by the time-hysteresis characteristic of vulcanized rubber compounds, arising through a dual nature, and causing them to manifest both elastic and plastic properties. Any instrument which applies load momentarily measures the almost purely elastic properties, while one which applies a more or less sustained load measures elastic properties modified by the material's partially plastic nature. These ideas are expressed from commercial and industrial viewpoints without regard to their possible deviations from the strict definitions accepted in physical science.

Effect of Antioxidants in Typical Rubber Stocks

1929 ◽  
Vol 2 (3) ◽  
pp. 456-461
Author(s):  
Marion C. Reed
Keyword(s):  
Inert Gas ◽  
Truck Tire ◽  
Rubber Compounds ◽  
Heavy Truck ◽  
Resistance To Heat

Abstract The results of these tests show that antioxidants are of value in stocks which become hot in service, such as bus tubes, belt frictions, and heavy truck tire treads. It is believed that aging at 90° C., both in air and in an inert gas free from oxygen, will be of assistance in separating the factors of oxidation and overcure in designing rubber compounds for resistance to heat.

Elastic Properties and Mechanical Losses in Rubbers in Complex Stressed State

1991 ◽  
Vol 19 (2) ◽  
pp. 100-112
Author(s):  
L. S. Priss ◽  
A. G. Shumskaya
Keyword(s):  
Stressed State ◽  
Elastic Properties ◽  
Measurement Data ◽  
Strain Range ◽  
Sufficient Accuracy ◽  
Elastic Potential ◽  
Complex Stressed State ◽  
Fourth Degree ◽  
Filled Rubber ◽  
Rubber Compounds

Abstract It is shown that in the strain range from 30% compression to 60% tension, the elastic potential of filled rubber compounds can be described with sufficient accuracy as a polynomial of the fourth degree with three independent constants. Methods to experimentally determine these constants are pointed out. A method for the calculation of mechanical losses in rubber compounds in a complex stressed state is suggested using the measurement data for simple modes of loading.

UNS T20812

Alloy Digest ◽  
1986 ◽  
Vol 35 (1) ◽  
Keyword(s):  
Elevated Temperatures ◽  
Heat Treating ◽  
Low Carbon ◽  
Good Resistance ◽  
High Hardenability ◽  
Temperature Changes ◽  
Extrusion Dies ◽  
Steel Mills ◽  
Heat Checking ◽  
Resistance To Heat

Abstract UNS No. T20812 is a low-carbon chromium-molybdenum-tungsten hot-work steel for general purposers. It is used for dies and tools that require high toughness. It has high hardenability and offers high resistance to softening in service at elevated temperatures. It also offers good resistance to heat checking and may be water cooled in service. It is suitable for hot-work applications involving severe conditions of shock and sudden temperature changes. Its many applications include hot shear blades, forging dies, extrusion dies, punches and other types of hot-work tools. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-453. Producer or source: Tool steel mills.

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