Adhesion of Vulcanized Rubber Surfaces: Characterization of Unmodified and Electron Beam Modified EPDM Surfaces and Their Co-vulcanization with Natural Rubber

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.

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Preparation and characterization of natural rubber compounds with filler of oil palm empty bunches powder and carbon black

Functional materials ◽

10.15407/fm27.01.140 ◽

2020 ◽

Vol 27 (1) ◽

Keyword(s):

Carbon Black ◽

Natural Rubber ◽

Oil Palm ◽

Rubber Compounds

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Characterization of AA7075/AA5356 gradient transition zone in an electron beam wire-feed additive manufactured sample

Materials Characterization ◽

10.1016/j.matchar.2020.110867 ◽

2021 ◽

Vol 172 ◽

pp. 110867

Author(s):

V. Utyaganova ◽

A. Filippov ◽

S. Tarasov ◽

N. Shamarin ◽

D. Gurianov ◽

...

Keyword(s):

Electron Beam ◽

Transition Zone ◽

Feed Additive ◽

Wire Feed

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Material parametrization of natural rubber based compound and characterization of crack propagation under consideration of dissipative effects

Journal of Rubber Research ◽

10.1007/s42464-021-00094-8 ◽

2021 ◽

Author(s):

Dan Pornhagen ◽

Konrad Schneider ◽

Markus Stommel

Keyword(s):

Energy Dissipation ◽

Crack Propagation ◽

Natural Rubber ◽

Experimental Tests ◽

Material Behavior ◽

Prony Series ◽

Material Forces ◽

Cracking Behavior ◽

Dissipative Effects

AbstractMost concepts to characterize crack propagation were developed for elastic materials. When applying these methods to elastomers, the question is how the inherent energy dissipation of the material affects the cracking behavior. This contribution presents a numerical analysis of crack growth in natural rubber taking energy dissipation due to the visco-elastic material behavior into account. For this purpose, experimental tests were first carried out under different load conditions to parameterize a Prony series as well as a Bergström–Boyce model with the results. The parameterized Prony series was then used to perform numerical investigations with respect to the cracking behavior. Using the FE-software system ANSYS and the concept of material forces, the influence and proportion of the dissipative components were discussed.

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Aging of Natural Rubber Vulcanizates in the Presence of Dithiocarbamates

Rubber Chemistry and Technology ◽

10.5254/1.3542442 ◽

1959 ◽

Vol 32 (3) ◽

pp. 739-747 ◽

Cited By ~ 4

Author(s):

J. R. Dunn ◽

J. Scanlan

Keyword(s):

Stress Relaxation ◽

Natural Rubber ◽

Protective Action ◽

Dicumyl Peroxide ◽

Vulcanized Rubber ◽

Aging Properties ◽

Photochemical Aging ◽

Natural Rubber Vulcanizates

Abstract The thermal and photochemical aging of extracted dicumyl peroxide-, TMTD (sulfurless)- and santocure-vulcanized rubber, in presence of a number of metal and alkylammonium dithiocarbamates, has been investigated by measurements of stress relaxation. The dithiocarbamates have a considerable protective action upon the degradation of peroxide- and TMTD-vulcanizates, but they accelerate stress decay in santocure-accelerated vulcanizates. The reasons for this behavior are discussed. It is suggested that the excellent aging properties of unextracted TMTD vulcanizates are due to the presence of zinc dimethyldithiocarbamate formed during vulcanization.

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