Some Properties of Two Vulcanized Pure Gum Compounds at Low Temperatures

1939 ◽  
Vol 12 (2) ◽  
pp. 370-380
Author(s):  
A. A. Somerville
Keyword(s):  
Tensile Strength ◽  
Low Temperatures ◽  
Rapid Cooling

Abstract (1) High and normal sulfur pure gum compounds became board-like and brittle within a few minutes when cooled at −60° C, yet when tested at this temperature they had an elongation of over 500% and tensile strength of over 5,000 lbs. per sq. in. (2) With decreasing temperature the two compounds gave increasing tensile strength and modulus and decreasing elongation. (3) Relatively high combined sulfur, i. e., up to over 8% on the rubber, was accompanied by a marked increase in hardness, even at temperatures no lower than −30° C. (4) A substitution of deproteinized rubber for smoked sheet appeared to give greater resistance to hardening at temperatures down to −40° C. (5) Unvulcanized, unmilled smoked sheet showed greater resistance to hardening on rapid cooling than the vulcanized compounds at all temperatures tested. This phenomenon, however, is not to be confused with that of ordinary frozen rubber, which is commonly observed at temperatures above −30° C.

Strength of Neoprene Compounds and the Effect of Salt Solutions

1983 ◽  
Vol 56 (4) ◽  
pp. 845-852 ◽  
Author(s):  
A. K. Bhowmick ◽  
A. N. Gent
Keyword(s):  
Tensile Strength ◽  
Lower Limit ◽  
Low Temperatures ◽  
Environmental Effect ◽  
Room Temperature ◽  
Characteristic Temperature ◽  
Salt Solutions ◽  
A Value ◽  
Fecl3 Solution ◽  
Tear Propagation

Abstract Soft CR vulcanizates resemble NR vulcanizates in many ways. Their tensile strength is high at low temperatures and drops sharply at a characteristic temperature to a value of about 1–1.5 MPa. Their tear resistance decreases smoothly as the temperature is raised and does not reach a lower limit, even at temperatures as high as 150°C. However, they show continuous tear propagation at room temperature under relatively large tear forces, whereas NR materials do not. This difference must reflect different strengths of the crystallites formed at the tear tip, those in CR being significantly weaker. Also, a specific environmental effect is noted: When immersed in solutions of FeCl3, the CR materials show more rapid tearing, and they tear at significantly lower forces than in water or in NaCl solutions (or in air). Although they swell continuously in water and in salt solutions, the rate of swelling seems far too low to account for the weakening observed. Moreover, the swelling is greater in water, whereas the weakening is specific to FeCl3 solution. It is attributed to a chemical reaction between FeCl3 and the CR molecule.

Considerations in Low-Temperature Mechanical Behavior of Polymer Composite Materials

2015 ◽  
Vol 760 ◽  
pp. 323-328
Author(s):  
Stefan Cotae ◽  
Constantin Popescu ◽  
Horatiu Iancau
Keyword(s):  
Tensile Strength ◽  
Mechanical Behavior ◽  
Fiber Orientation ◽  
Low Temperatures ◽  
Composite Structures ◽  
Room Temperature ◽  
Experimental Program ◽  
Independent Variables ◽  
Factorial Method ◽  
Degree Of Reinforcement

In this paper it has been sought to highlight the mechanical behavior of composite structures at low temperatures compared to mechanical behavior at room temperature. For researches an experimental program has been conceived and built using factorial method. In this method, as dependent variable was taken the tensile strength (σr), while as independent variables were taken: the fiber orientation angles (θ), the degree of reinforcement (Mf) of the composite structure and the temperature (t) at which the tests were carried out (+25°C,-25°C and-50°C respectively). It has been used a complex experimental installation, specific to tests at low temperatures.

γ-U phase in U-Pt system retained to low temperatures by means of rapid cooling

2016 ◽  
Vol 479 ◽  
pp. 287-294 ◽  
Author(s):  
N.-T.H. Kim-Ngan ◽  
M. Paukov ◽  
R. Tarasenko ◽  
V. Tkáč ◽  
P. Minarik ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Rapid Cooling

The fatigue and ultimate tensile strengths of metals between 4⋅2 and 293° K

1957 ◽  
Vol 242 (1229) ◽  
pp. 203-211 ◽  
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Ultimate Tensile Strength ◽  
Brittle Fracture ◽  
Low Temperatures ◽  
Fatigue Characteristics

The fatigue of copper, silver, gold, aluminium, magnesium, zinc and iron has been investigated at 4⋅2, 20, 90 and 293° K. Except for zinc and iron, which exhibit brittle fracture at low temperatures, the fatigue characteristics improve very considerably as the temperature is reduced. The ultimate tensile strength of all the metals was also taken at each temperature and there was shown to be a marked correlation between the increase in the tensile strength at low temperatures and the increase in the fatigue strength. The results are discussed with reference to current ideas on the mechanism of fatigue.

ALUMINUM 2021

Alloy Digest ◽  
1969 ◽  
Vol 18 (9) ◽  
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Low Temperatures ◽  
Heat Treating ◽  
Notch Toughness ◽  
Good Corrosion Resistance ◽  
Temperature Performance ◽  
Aluminum Company

Abstract ALUMINUM 2021 is a cryogenic alloy whose ductility and relative notch toughness are not reduced as the tensile strength increases at the low temperatures. It is tough, weldable, and has good corrosion resistance. This datasheet provides information on composition, physical properties, hardness, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-190. Producer or source: Aluminum Company of America.

A Study of the Rubber-Metal Bond

1946 ◽  
Vol 19 (4) ◽  
pp. 956-967
Author(s):  
S. Buchan ◽  
J. R. Shanks
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Low Temperatures ◽  
Moderate Increase ◽  
Progressive Reduction ◽  
Bonding Agents ◽  
Metal Bond ◽  
Permanent Set ◽  
Vulcanized Rubber ◽  
Derivatives Of

Abstract Although the practice of bonding rubber to metal has been in use for many years, no theories appear to have been advanced which explain adequately the mechanism of bonding. It has been stated that the brass bond between rubber and metal functions through chemical linkages, but this can only be regarded as tentative and has yet to be proved. No attempt has been made to find out how ebonite functions as a bonding medium or the more recently discovered derivatives of rubber, such as sulfonated rubber, chlorinated rubber, and rubber hydrohalides. Until it is properly elucidated just how bonding agents do act, further logical development of improved bonding media cannot be pursued. It is intended in this paper to show how the rubber-metal bond behaves at subnormal temperatures and how a low temperature technique may be used for studying the mechanism of bonding. The effect of low temperatures on the tensile strength and associated properties of vulcanized rubber, such as hardness, permanent set, flexibility, resilience and flexing, has been dealt with fairly comprehensively in the literature. Progressive reduction in temperature leads to only a moderate increase, for example, in tensile strength, until the point is reached at which the rubber stiffens and freezes, when a marked increase occurs. Examination of a brass-bonded unit at low temperatures revealed that the graph obtained for bond strength was very similar in slope and character to that for tensile strength. The similarity is illustrated by the data in Table 1 and in Figure 1.

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