Measurement of Rubber Tack

1965 ◽  
Vol 38 (4) ◽  
pp. 689-699 ◽  
Author(s):  
J. D. Skewis
Keyword(s):  
Natural Rubber ◽  
Wide Temperature Range ◽  
Complete Separation ◽  
Empirical Treatment ◽  
Force Development ◽  
Temperature Range ◽  
Polymer Compound ◽  
Time Required ◽  
Increasing Temperature ◽  
Predetermined Time

Abstract An instrument for measurement and study of tack of rubber compositions is described. The method involves pressing together two specimens of polymer compound with a chosen force for a predetermined time, and then measuring the time to separate them with a preselected force. Development of tacky adhesion is related to the product of force and a function of time that the specimens are pressed together. The measure of adhesion also involves the product of force and a function of time required for complete separation. Empirical treatment yields an equation to describe tacky behavior of a rubber composition in terms of the ratio of these products of force and time, the ratio being designated as the tack index of that composition. An example is given by comparing tack of SBR with that of natural rubber. SBR exhibits a tack index of about unity over a wide temperature range while natural rubber has a large tack index at 25° C, which decreases with increasing temperature. It is suggested that the excellent tack of natural rubber is due to crystallization with elongation.

Damping Capacity of Fe-Ga Alloys

2011 ◽  
Vol 228-229 ◽  
pp. 937-941 ◽  
Author(s):  
Fang Mei Ling ◽  
Jie Zhu ◽  
Li Ji Heng ◽  
Gao Xue Xu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Wide Temperature Range ◽  
Room Temperature ◽  
Damping Capacity ◽  
Torsion Pendulum ◽  
Temperature Peak ◽  
Temperature Range ◽  
Computer Controlled ◽  
Increasing Temperature

The damping capacity of Fe-Ga rods and sheets has been studied using a computer-controlled automatic inverted torsion pendulum instruments in a wide temperature range in a series of frequency. The frequency and temperature has different influence on the damping capacity of solidified Fe83Ga17 rods and (Fe83Ga17)97.25Cr2B0.75 sheets. The damping capacity of all specimens increased with frequencies. The solidified Fe-Ga rods showed an obvious low-temperature peak and a potential high-temperature peak with increasing temperature. However, the damping capacity of Fe-Ga sheets kept steady in a wide temperature range and then rapidly increased on further heating above 400°C. Damping capacity of about 0.02 was obtained in both Fe-Ga rods and sheets at temperatures from room temperature to 500°C. Thus, The Fe-Ga alloys are considered to be a class of promising high damping alloys.

The Effect of Organic Accelerators on the Temperature Coefficient of Vulcanization

1938 ◽  
Vol 11 (1) ◽  
pp. 101-106 ◽  
Author(s):  
K. W. Eliel
Keyword(s):  
Critical Temperature ◽  
Temperature Coefficient ◽  
Wide Temperature Range ◽  
Similar Activity ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Constant Proportion ◽  
Action Type ◽  
Delayed Action ◽  
Time Required

Abstract (1) The temperature coefficient of vulcanization to a standard modulus is 2.0 in the presence of mercaptobenzothiazole, Ureka, Ureka White, and Vulcafor D. A. (2) The temperature coefficients of vulcanization in the presence of all accelerators tested, including those of delayed action type, are constant over a wide temperature range (110–150° C). None of the accelerators appears to have a critical temperature. (3) Differences between the rates at which modulus develops with accelerators of similar activity may account for the fact that some induce scorching on the compounding mill, whereas others do not. (4) At all temperatures investigated, the period of delay of a delayed action accelerator may represent a constant proportion of the total time required to reach a definite state of cure, as indicated by modulus.

Crystallization and Strength of Natural Rubber and Synthetic cis-1,4-Polyisoprene

1998 ◽  
Vol 71 (4) ◽  
pp. 668-678 ◽  
Author(s):  
A. N. Gent ◽  
S. Kawahara ◽  
J. Zhao
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Melting Temperature ◽  
Wide Temperature Range ◽  
Critical Factor ◽  
Tear Strength ◽  
Temperature Range ◽  
Low Speeds ◽  
Structural Irregularities ◽  
Lower Tensile Strength

Abstract Crosslinked samples of natural rubber (NR, SMR-5L) and a synthetic cis-1,4-polyisoprene (IR, Natsyn 2200, The Goodyear Tire & Rubber Company) were crystallized at −25 °C at various strains, and then slowly melted. Crystallization was somewhat slower for IR under all conditions, taking two to three times as long as for NR crosslinked to the same degree. The melting temperature was also a few degrees lower. These effects are consistent with the presence of a small fraction of non-cis material in the IR molecule. Measurements of tensile strength and tear strength were made over a wide temperature range. The results were closely similar for the two materials at low rates of stretching although the abrupt fall in tensile strength associated with a failure to crystallize occurred at slightly lower temperatures for IR. Tear strength at low speeds showed a steady fall on raising the temperature, with little difference between the two materials. However, at high rates of strain the IR materials appeared to have significantly lower tensile strength, and at high tear speeds the tear strength was markedly lower, about one-half of that for NR. Thus, the minor structural irregularities in IR appear to be of little consequence at low rates of strain, but cause significant weakening at high rates, when the lower rate of crystallization is inferred to become a critical factor.

Modeling of some physicochemical properties in the liquid Au–Bi–Sn alloys relevant for Pb-free soldering

2017 ◽  
Vol 16 (02) ◽  
pp. 1750015 ◽  
Author(s):  
Rachida M’chaar ◽  
Salma Belmoujoud ◽  
Abdelaziz Sabbar ◽  
Mouloud El Moudane ◽  
Ahmed Ghanimi
Keyword(s):  
Physicochemical Properties ◽  
Molar Volume ◽  
Cross Sections ◽  
Wide Temperature Range ◽  
Binary Systems ◽  
Ternary Systems ◽  
Temperature Range ◽  
Experimental Values ◽  
Increasing Temperature ◽  
Good Agreement

In this paper, some geometrical models such as Kohler, Muggianu, Toop, and Hillert have been used to estimate the molar volume of Au–Bi–Sn ternary systems based on the data of sub-binary systems over a wide temperature range (673–973[Formula: see text]K). The density of Au–Bi–Sn alloys was calculated from the calculated molar volume and using theoretical equation along three cross-sections [Formula: see text]/[Formula: see text]/2, 1/1 and 2/1. In addition, the viscosity of Au–Bi–Sn alloys was calculated by using Seetharaman–Sichen equation over a wide temperature range (673–1273[Formula: see text]K). The density of these alloys show linear dependence on temperature for all investigated compositions, while the molar volumes increase with increasing temperature and Sn compositions. The results show, as a function of temperature, that the increase in concentration of tin influences the viscosity of the Au–Bi–Sn alloys. The calculated values of density of Au–Bi–Sn alloys are compared with the experimental values reported in the literature, and a good agreement was observed.

Fibre-optic temperature sensor with wide temperature range characteristics

1987 ◽  
Vol 134 (5) ◽  
pp. 291 ◽  
Author(s):  
K.T.V. Grattan ◽  
J.D. Manwell ◽  
S.M.L. Sim ◽  
C.A. Willson
Keyword(s):  
Wide Temperature Range ◽  
Temperature Sensor ◽  
Fibre Optic ◽  
Temperature Range

Enabling highly reversible sodium metal cycling across a wide temperature range with dual-salt electrolytes

2021 ◽  
Author(s):  
Akila C. Thenuwara ◽  
Pralav P. Shetty ◽  
Neha Kondekar ◽  
Chuanlong Wang ◽  
Weiyang Li ◽  
...  
Keyword(s):  
Wide Temperature Range ◽  
High Energy ◽  
Liquid Electrolyte ◽  
Metal Cycling ◽  
Temperature Range ◽  
Sodium Metal ◽  
Wide Range

A new dual-salt liquid electrolyte is developed that enables the reversible operation of high-energy sodium-metal-based batteries over a wide range of temperatures down to −50 °C.

Magnetic anomalies, chemical and magnetic properties at wide temperature range (15–1000 K) in LiSrxFe5-xO8 (x = 0, 0.025, 0.05)

2021 ◽  
Vol 859 ◽  
pp. 158290
Author(s):  
S. Udhayakumar ◽  
G. Jagadish Kumar ◽  
E. Senthil Kumar ◽  
M. Navaneethan ◽  
K. Kamala Bharathi
Keyword(s):  
Magnetic Properties ◽  
Wide Temperature Range ◽  
Magnetic Anomalies ◽  
Temperature Range
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