The Fusion Curve of Natural Rubber

1931 ◽  
Vol 4 (2) ◽  
pp. 211-212
Author(s):  
G. v. Susich
Keyword(s):  
Melting Point ◽  
Specific Gravity ◽  
Natural Rubber ◽  
Specific Heat ◽  
Light Absorption ◽  
Temperature Range

Abstract Katz has shown that the melting point of frozen raw rubber is 35°–38° C. when determined by the disappearance of the crystal interferences upon warming. The discontinuous changes in the specific gravity, in the hardness, and in the light absorption, as well as the γ-anomaly of the specific heat, lie within this temperature range.

scholarly journals The Specific Heat of Saline Ice

1975 ◽  
Vol 14 (72) ◽  
pp. 459-465 ◽  
Author(s):  
Bharat Dixit ◽  
E. R. Pounder
Keyword(s):  
Theoretical Model ◽  
Melting Point ◽  
Specific Heat ◽  
Experimental Results ◽  
Temperature Range ◽  
Calorimetric Experiment

A calorimetric experiment was performed to determine empirically the dependence of the specific heat of ice with salinity 0-10‰ over the temperature range from –23° C to the melting point The experimental results agree with the theoretical model determined by Schwerdtfeger (1963) for calculating the specific heat except within several degrees of the melting point and for very pure ice.

Interactions of Copper with Interlayer Dielectrics and Adhesion Promoters / Diffusion Barriers.

1990 ◽  
Vol 203 ◽  
Author(s):  
B. Arcot ◽  
Y.T. Shy ◽  
S.P. Murarka ◽  
C. Shepard ◽  
W.A. Lanford
Keyword(s):  
Melting Point ◽  
Specific Heat ◽  
Diffusion Barrier ◽  
Metal Film ◽  
Diffusion Barriers ◽  
Adhesion Promoter ◽  
Adhesion Promoters ◽  
Inorganic Oxides ◽  
Temperature Range ◽  
Dielectric Layers

ABSTRACTCopper with its high conductivity, specific heat and melting point (compared to Al), is being investigated as the interconnection metal for applications both on and off the chip. Such interconnection wirings will be seperated by the dielectric layers which could be either polymers or inorganic oxides like SiO2. In such applications an adhesion promoter, which may also work as a diffusion barrier, maybe used between the dielectric and the metal film. An investigation of the diffusion and interaction of Copper with such dielectrics and insulators has been carried out in the temperature range of 200 – 500 ºC. Specifically, interactions of Copper with SiO2'P—glass, Polyimidesiloxane and Magnesium are investigated. Results of these studies will be presented and discussed.

scholarly journals The Specific Heat of Saline Ice

1975 ◽  
Vol 14 (72) ◽  
pp. 459-465 ◽  
Author(s):  
Bharat Dixit ◽  
E. R. Pounder
Keyword(s):  
Theoretical Model ◽  
Melting Point ◽  
Specific Heat ◽  
Experimental Results ◽  
Temperature Range ◽  
Calorimetric Experiment

A calorimetric experiment was performed to determine empirically the dependence of the specific heat of ice with salinity 0-10‰ over the temperature range from –23° C to the melting point The experimental results agree with the theoretical model determined by Schwerdtfeger (1963) for calculating the specific heat except within several degrees of the melting point and for very pure ice.

The Crystallization of Weakly Vulcanized Rubber by Pressure

1940 ◽  
Vol 13 (1) ◽  
pp. 48-48 ◽  
Author(s):  
P. A. Thiessen ◽  
W. Kirch
Keyword(s):  
Melting Point ◽  
Natural Rubber ◽  
Crystalline Phase ◽  
Normal Pressure ◽  
Latex Film ◽  
X Rays ◽  
Amorphous Substance ◽  
Temperature Range ◽  
Vulcanized Rubber

Abstract Crystallization can be brought about in weakly vulcanized rubber by the method described by Thiessen and Kirsch for natural rubber. When samples of this type of vulcanized rubber were exposed to x-rays below + 6° C, but not under pressure, then Debye-Scherrer diagrams corresponding to those of a crystallized latex film were obtained. To determine the influence of pressure on these vulcanizates, samples were subjected to pressure on all sides in the chambers of the pressure apparatus described in the earlier work. After having been exposed for 100 days the sample which had been kept at + 6° C under 30 atmospheres' pressure showed a very marked Debye-Scherrer diagram, whereas samples kept at the same temperature but at normal pressure showed only the halo of an amorphous substance. Consequently pressure has an influence on the crystallization of vulcanized rubber as well as of raw rubber. The melting point of the crystalline phase lies between + 11° C. and +13° C. Obviously then an increase in pressure raises the temperature range of supercooling.

Thermodynamic Properties of Natural Rubber and Isoprene

1966 ◽  
Vol 39 (1) ◽  
pp. 143-148 ◽  
Author(s):  
R. W. Warfield ◽  
M. C. Petree
Keyword(s):  
Free Energy ◽  
Glass Transition ◽  
Thermodynamic Properties ◽  
Natural Rubber ◽  
Specific Heat ◽  
Gibbs Free Energy ◽  
Kcal Mole ◽  
Specific Heat Data ◽  
Temperature Range ◽  
Heat Data

Abstract Using published specific heat data, the entropy, enthalpy, and Gibbs free energy of natural rubber (NR) have been calculated over the temperature range 0 to 320° K. The thermodynamic function Cp/T as a function of T calculated for NR exhibits a maximum at 50° K and another maximum at 210° K, which is associated with the glass transition. The number of classically vibrating units per repeating unit of NR is 6.61 at 300° K. These functions have also been calculated for isoprene over the temperature range 0 to 300° K. At 298.16° K the entropy of polymerization was found to be 24.00 cal mole−1deg−1 and the free energy of polymerization − 10.7 kcal/mole.

Specific heat of Teflon-40 and BF-2 glue in the 10?300�K temperature range

1972 ◽  
Vol 22 (4) ◽  
pp. 450-451 ◽  
Author(s):  
V. S. Krylovskii ◽  
V. I. Ovcharenko ◽  
V. I. Khotkevich
Keyword(s):  
Specific Heat ◽  
Temperature Range

The influence of crystalline texture on the tensile properties of natural rubber. I

1974 ◽  
Vol 338 (1615) ◽  
pp. 459-478 ◽  
Keyword(s):  
Glass Transition ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Amorphous Phase ◽  
Crystalline Phase ◽  
Full Range ◽  
Glassy Matrix ◽  
Tensile Behaviour ◽  
Crystalline Morphology ◽  
Temperature Range

The crystalline morphologies that are attainable in samples of natural rubber (n. r.), by extending the samples prior to crystallization, are reviewed. Specimens covering the full range of crystalline morphologies possible have been prepared and tensile tested between – 120 and – 26 °C. The tensile behaviour of crystalline samples is compared and contrasted with that of oriented, but non-crystalline, identical natural rubber in the same temperature range. It is found that the tensile behaviour of semi-crystalline n. r. is dominated by the amorphous phase throughout the temperature range – 120 to – 26 °C. At temperatures above the glass transition temperature ( T g ) of the amorphous phase, the crystalline phase acts mainly as a diluent of the amorphous phase. At temperatures below T g , where the crystalline phase is set in a glassy matrix, it is found that the crystalline morphology does significantly affect the tensile behaviour. Attempts are made to differentiate the effects of crystallinity, crystalline morphology and orientation of the amorphous phase on the tensile properties of natural rubber.

THE COMBINED ANALYSIS OF SPECIFIC HEAT AND THERMAL EXPANSION OF Nd1−xLuxMn2 COMPOUNDS

1993 ◽  
Vol 07 (01n03) ◽  
pp. 810-813
Author(s):  
N.H. KIM-NGAN ◽  
P.E. BROMMER ◽  
J.J.M. FRANSE
Keyword(s):  
Magnetic Properties ◽  
Thermal Expansion ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Crystal Field ◽  
Spin Fluctuation ◽  
Spin Reorientation ◽  
Antiferromagnetic Order ◽  
Combined Analysis ◽  
Temperature Range

Specific heat and thermal expansion measurements have been performed on Nd1−xLUxMn2 in the temperature range between 1.5K and 300K. Below 10K, anomalies are observed which are ascribed to a spin reorientation of the Nd sublattice. These anomalies are only slightly affected by the substitution of Nd by Lu. Large effects, however, are observed on the magnetic properties of the Mn sublattice. The antiferromagnetic order disappears for x exceeding 0.30. The data are analysed in terms of Grüneisen parameters. In the paramagnetic compound LuMn2, a spin-fluctuation contribution to the thermodynamic properties is observed. In the Nd-containing compounds, distinct contributions from the crystal field acting on the Nd ions can be distinguished. The variation of the magnetic properties of the Mn sublattice with the concentration of Lu is discussed.

Specific heats of polymer powders by differential scanning calorimetry

1982 ◽  
Vol 60 (14) ◽  
pp. 1853-1856 ◽  
Author(s):  
Eva I. Vargha-Butler ◽  
A. Wilhelm Neumann ◽  
Hassan A. Hamza
Keyword(s):  
Differential Scanning Calorimetry ◽  
Specific Heat ◽  
Scanning Calorimetry ◽  
Temperature Range ◽  
Specific Heats ◽  
Powdered Form ◽  
Polymer Powders

The specific heats of five polymers were determined by differential scanning calorimetry (DSC) in the temperature range of 300 to 360 K. The measurements were performed with polymers in the form of films, powders, and granules to clarify whether or not DSC specific heat values are dependent on the diminution of the sample. It was found that the specific heats for the bulk and powdered form of the polymer samples are indistinguishable within the error limits, justifying the determination of specific heats of powders by means of DSC.

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