The Proportion of Crystalline and Amorphous Components in Stretched Vulcanized Rubber

1946 ◽  
Vol 19 (4) ◽  
pp. 1124-1136
Author(s):  
A. J. Wildschut
Keyword(s):  
Tensile Strength ◽  
Amorphous Phase ◽  
Distance Function ◽  
Close Agreement ◽  
Crystalline Material ◽  
Temperature Relation ◽  
X Ray ◽  
Vulcanized Rubber ◽  
Equal Importance

Abstract Determinations of the tension-temperature relation of stretched vulcanized rubber can provide us with data about the proportion of crystalline and amorphous components. The amount of crystalline material appears to be 30–32 per cent at 600 per cent elongation and at 20° C. An expression is derived relating percentage of crystalline material and temperature. The results are in close agreement with those of x-ray measurements carried out by Goppel, but diverge largely from those obtained by Field. The cause of this difference is not yet clear. Stretched vulcanized rubber consists of a predominating amorphous phase, with crystallites embedded in it. On stretching orientation occurs, and a systematic addition of secondary valency forces is possible. This is the main cause of the existence of a certain tensile strength. Crystallization, though important as an indication on orientation, is more or less an incidental phenomenon. The distance function of the secondary forces may be of equal importance with the orientation.

X-Ray Study of the Crystallization of Vulcanized Rubber during Stretching. II.

1951 ◽  
Vol 24 (3) ◽  
pp. 541-549 ◽  
Author(s):  
V. I. Kasotochkin ◽  
B. V. Lukin
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Crystal Formation ◽  
Oxidative Destruction ◽  
Ray Method ◽  
X Ray ◽  
Vulcanized Rubber ◽  
Crystal Content

Abstract 1. The relation between the crystal content of stretched vulcanizates to the time of vulcanization for different mixtures of natural rubber was studied by the x-ray method. 2. It was shown that the tensile strength is a function of the crystal content of the stretched vulcanizate and of the total time of vulcanization. 3. The nature of crystal formation depends on the following factors: changes of density of the network of sulfur bridges, their distribution, the degree of oxidative destruction, and the quantity of bound sulfur which has not formed bridges between the molecular chains.

An X-Ray Study of the Proportion of Crystalline and Amorphous Components in Stretched Rubber

1941 ◽  
Vol 14 (3) ◽  
pp. 555-571 ◽  
Author(s):  
J. E. Field
Keyword(s):  
Physical Properties ◽  
Structural Characteristics ◽  
Quantitative Measure ◽  
Crystalline Material ◽  
Amorphous Halo ◽  
X Ray ◽  
Vulcanized Rubber ◽  
Maximum Value ◽  
Degree Of Crystallization ◽  
And Performance

Abstract A method is described for obtaining a quantitative measure of crystalline hydrocarbon present in stretched rubber samples by comparing the intensities of the diffraction spots and the amorphous halo appearing in the x-ray diagrams. This method has been applied to a study of the crystallinity of stretched vulcanized rubber as it is affected by different vulcanization accelerators, variations in extension, temperature, and cure. To illustrate a connection between the physical performance of a rubber vulcanizate and its degree of crystallization, measurements were made of the relation of crystallinity to creep when the rubber was stretched to different initial elongations under constant loads. The creep as a function of the elongation has a maximum value at the same intermediate elongation for which crystallization becomes appreciable. At higher elongations, increased crystallinity results in a diminution of the creep. The ultimate strength and extensibility generally associated with stretched vulcanized rubber is the result of the combined effect of primary valence cross-linkages formed by vulcanization and the formation of crystallites caused by stretching. Crystallization is an important factor in maintaining the relatively high strengths of vulcanizates having a greater range of extensibilities. In general, the physical properties and performance of vulcanized rubber is related to the amount of crystalline material formed on stretching, which depends on the structural characteristics of the vulcanizate.

scholarly journals Bending strength and phase composition of cement stone subjected to loading at an early stage

2018 ◽  
Vol 193 ◽  
pp. 03031 ◽  
Author(s):  
Yuriy Galkin ◽  
Sergey Udodov
Keyword(s):  
Tensile Strength ◽  
Phase Composition ◽  
Amorphous Phase ◽  
Bending Strength ◽  
Early Stage ◽  
Cement Stone ◽  
X Ray ◽  
Early Loading ◽  
Strength In Bending ◽  
Control Samples

The article deals with the results of comparative tests of the phase composition of cement stone distinguished by strength under bending and compression. The comparison has been made between samples subjected to early loading and control samples. An increase in tensile strength in bending of samples subjected to early loading was recorded. The difference in compressive strengths does not exceed 5%. X-ray phase analysis indicates amorphous phase increase with the growth of strength properties, which is manifested in increased intensity of the amorphous phase arc in the X-ray diffraction pattern. The highest peak of the curve corresponds to the maximum flexural strength of the entire row of samples. Among the samples subjected to early loading, the peak intensity of the group of crystal tobermorites with interplanar distances 11.5-11.3Å and 12.5Å appeared to be higher than the intensity of the control samples. It was proposed that the amorphous structure affects the increase in tensile strength in bending of cement stone subjected to early loading.

X-Ray Investigation of the Crystallization of Vulcanized Rubber on Stretching

1948 ◽  
Vol 21 (3) ◽  
pp. 621-626 ◽  
Author(s):  
B. V. Lukin ◽  
V. I. Kasatochkin
Keyword(s):  
Tensile Strength ◽  
Crystalline Phase ◽  
Oxidative Degradation ◽  
Point Of View ◽  
Crystal Formation ◽  
Stress Strain ◽  
X Ray ◽  
Vulcanized Rubber ◽  
Cross Links ◽  
Ray Methods

Abstract 1. x-Ray methods have been used to investigate the amount of crystalline phase in stretched samples as a function of the vulcanization time. 2. Curves relating the percentage of crystalline phase to the vulcanization time have sharply defined maxima. 3. A comparison of the curves relating tensile strength to vulcanization time with the curves of crystal formation shows their analogous character, the position of the maxima approximately corresponding to one and the same vulcanization time. 4. The position of the maxima on the curves of crystal formation is not related to the degree of stretching. 5. The effect of accelerators is to shift the maximum on the curve of crystal formation to the region of short vulcanization times and to increase the percentage of crystalline phase. 6. The curves of crystal formation and of tensile strength, and thus the behavior of the stress-strain curves for various vulcanization times, is interpreted from the point of view of the existence of two processes—the process of forming a network of cross-links by the interaction of rubber with sulfur, and the process of oxidative degradation of the rubber.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

The Application of X-Ray Diffraction at Elevated Temperatures to Study the Mechanism of Formation of Sodium Tripolyphosphate

1961 ◽  
Vol 5 ◽  
pp. 276-284
Author(s):  
E. L. Moore ◽  
J. S. Metcalf
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Amorphous Phase ◽  
Elevated Temperatures ◽  
Sodium Tripolyphosphate ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Temperature Form ◽  
High Temperature Form

AbstractHigh-temperature X-ray diffraction techniques were employed to study the condensation reactions which occur when sodium orthophosphates are heated to 380°C. Crystalline Na4P2O7 and an amorphous phase were formed first from an equimolar mixture of Na2HPO4·NaH2PO4 and Na2HPO4 at temperatures above 150°C. Further heating resulted in the formation of Na5P3O10-I (high-temperature form) at the expense of the crystalline Na4P4O7 and amorphous phase. Crystalline Na5P3O10-II (low-temperature form) appears after Na5P3O10-I.Conditions which affect the yield of crystalline Na4P2O7 and amorphous phase as intermediates and their effect on the yield of Na5P3O10 are also presented.

Characteristic properties of AlTiN and TiN coated HSS materials

2015 ◽  
Vol 67 (2) ◽  
pp. 172-180 ◽  
Author(s):  
Mumin Sahin ◽  
Cenk Misirli ◽  
Dervis Özkan
Keyword(s):  
Surface Roughness ◽  
Tensile Strength ◽  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
Wear Properties ◽  
Content Type ◽  
X Ray ◽  
Number Of Cycles ◽  
Future Work

Purpose – The purpose of this paper is to examine mechanical and metallurgical properties of AlTiN- and TiN-coates high-speed steel (HSS) materials in detail. Design/methodology/approach – In this study, HSS steel parts have been processed through machining and have been coated with AlTiN and TiN on physical vapour deposition workbench at approximately 6,500°C for 4 hours. Tensile strength, fatigue strength, hardness tests for AlTiN- and TiN-coated HSS samples have been performed; moreover, energy dispersive X-ray spectroscopy and X-ray diffraction analysis and microstructure analysis have been made by scanning electron microscopy. The obtained results have been compared with uncoated HSS components. Findings – It was found that tensile strength of TiAlN- and TiN-coated HSS parts is higher than that of uncoated HSS parts. Highest tensile strength has been obtained from TiN-coated HSS parts. Number of cycles for failure of TiAlN- and TiN-coated HSS parts is higher than that for HSS parts. Particularly TiN-coated HSS parts have the most valuable fatigue results. However, surface roughness of fatigue samples may cause notch effect. For this reason, surface roughness of coated HSS parts is compared with that of uncoated ones. While the average surface roughness (Ra) of the uncoated samples was in the range of 0.40 μm, that of the AlTiN- and TiN-coated samples was in the range of 0.60 and 0.80 μm, respectively. Research limitations/implications – It would be interesting to search different coatings for cutting tools. It could be the good idea for future work to concentrate on wear properties of tool materials. Practical implications – The detailed mechanical and metallurgical results can be used to assess the AlTiN and TiN coating applications in HSS materials. Originality/value – This paper provides information on mechanical and metallurgical behaviour of AlTiN- and TiN-coated HSS materials and offers practical help for researchers and scientists working in the coating area.

scholarly journals Anisotropy of the galaxy cluster X-ray luminosity–temperature relation

2018 ◽  
Vol 611 ◽  
pp. A50 ◽  
Author(s):  
Konstantinos Migkas ◽  
Thomas H. Reiprich
Keyword(s):  
Galaxy Clusters ◽  
Statistical Significance ◽  
Cosmological Parameters ◽  
Galaxy Cluster ◽  
Luminosity Distance ◽  
Temperature Relation ◽  
X Ray ◽  
Two Samples ◽  
The Galaxy ◽  
Group A

We introduce a new test to study the cosmological principle with galaxy clusters. Galaxy clusters exhibit a tight correlation between the luminosity and temperature of the X-ray-emitting intracluster medium. While the luminosity measurement depends on cosmological parameters through the luminosity distance, the temperature determination is cosmology-independent. We exploit this property to test the isotropy of the luminosity distance over the full extragalactic sky, through the normalization a of the LX–T scaling relation and the cosmological parameters Ωm and H0. To this end, we use two almost independent galaxy cluster samples: the ASCA Cluster Catalog (ACC) and the XMM Cluster Survey (XCS-DR1). Interestingly enough, these two samples appear to have the same pattern for a with respect to the Galactic longitude. More specifically, we identify one sky region within l ~ (−15°, 90°) (Group A) that shares very different best-fit values for the normalization of the LX–T relation for both ACC and XCS-DR1 samples. We use the Bootstrap and Jackknife methods to assess the statistical significance of these results. We find the deviation of Group A, compared to the rest of the sky in terms of a, to be ~2.7σ for ACC and ~3.1σ for XCS-DR1. This tension is not significantly relieved after excluding possible outliers and is not attributed to different redshift (z), temperature (T), or distributions of observable uncertainties. Moreover, a redshift conversion to the cosmic microwave background (CMB) frame does not have an important impact on our results. Using also the HIFLUGCS sample, we show that a possible excess of cool-core clusters in this region, is not able to explain the obtained deviations. Furthermore, we tested for a dependence of the results on supercluster environment, where the fraction of disturbed clusters might be enhanced, possibly affecting the LX–T relation. We indeed find a trend in the XCS-DR1 sample for supercluster members to be underluminous compared to field clusters. However, the fraction of supercluster members is similar in the different sky regions, so this cannot explain the observed differences, either. Constraining Ωm and H0 via the redshift evolution of LX–T and the luminosity distance via the flux–luminosity conversion, we obtain approximately the same deviation amplitudes as for a. It is interesting that the general observed behavior of Ωm for the sky regions that coincide with the CMB dipole is similar to what was found with other cosmological probes such as supernovae Ia. The reason for this behavior remains to be identified.

Characterizing the Thermomechanical Degradation of a Filled Elastomer by Morphology and X Ray Photoelectron Spectroscopy

2001 ◽  
Vol 702 ◽  
Author(s):  
Giovanni F Crosta ◽  
Art J Nelson ◽  
Marina C Camatini
Keyword(s):  
Photoelectron Spectroscopy ◽  
Intrinsic Property ◽  
Binding Energies ◽  
Structural Domain ◽  
X Ray ◽  
Vulcanized Rubber ◽  
A Value ◽  
Debris Particles ◽  
Morphological Descriptor ◽  
Microscopy Images

ABSTRACTThree types of debris particles, denoted by L2, H2 and K3 respectively, originated from the abrasion of silica-filled, vulcanized rubber under different test conditions (severity) were analyzed and compared. The structural fractal dimension, DFS, of the particle perimeter was chosen as a morphological descriptor (but not necessarily as an intrinsic property of the fractured material !). Said dimension was estimated by processing light microscopy images. A value of the morphological threshold, TST, which separates the textural from the structural domain in the RICHARDSON plot was determined in order to maximize discrimination between the three particle types and rank them by increasing values of DFS. Particles from the highest severity test (K3) exhibited the highest value of DFS. X ray photoelectron spectroscopy (XPS) provided elemental composition, core level binding energies and the speciation of C, N, O, Si and S. As a result, L2 debris was found to originate from two processes: fracture of rubber and segregation of extender oil. Evidence has come both from morphology and XPS. Particles of H2 and K3 were ascribed to fracture alone. Comparison between K3 and the reference material, rasped rubber (RAS), shows the following: a) increase of the [S]/[C] surface atomic concentration ratio from RAS to K3; b) existence of multiple bonding states of S in K3 with energy peaking at 162.9 ± 0.3 eV ([-S-S-]n); c) weak contribution of R-S-O-R oxidized S species in K3 at 165 eV, not seen in RAS; d) no evidence of either SO3 or SO4 groups in any material. Although preliminary, these results prove the ability of morphological analysis and XPS to characterize the surface properties of debris particles non destructively.

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