Mastication of Elastomers II. Cold Mastication of Natural Rubber

1963 ◽  
Vol 36 (1) ◽  
pp. 102-110 ◽  
Author(s):  
G. M. Bristow
Keyword(s):  
Low Temperature ◽  
Natural Rubber ◽  
Thermal Oxidation ◽  
Chain Scission ◽  
Oxidative Process ◽  
Radical Acceptor

Abstract The cold mastication of natural rubber in oxygen is shown to proceed rather more rapidly than that in air. Reasons for this difference are considered. Mastication under these conditions is considered as a low temperature oxidative process and consistent with this the subsequent reactions of RO2 radicals produced by mechanical shear are shown to lead to some additional chain scission. The thermal oxidation of rubber masticated in oxygen is rather more rapid than that of rubber masticated in nitrogen in the presence of a radical acceptor.

Aging Behaviors of Natural Rubber in Isolation Bearings

2010 ◽  
Vol 163-167 ◽  
pp. 3343-3347 ◽  
Author(s):  
Hao Sheng Gu ◽  
Yoshito Itoh
Keyword(s):  
Low Temperature ◽  
Natural Rubber ◽  
Acid Rain ◽  
Thermal Oxidation ◽  
Salt Water ◽  
Accelerated Aging ◽  
Test Results ◽  
Significant Drop ◽  
Degradation Factor

This paper attempts to reveal the aging behaviors of natural rubber (NR) used in isolation bearings. Using various degradation factors like thermal oxidation, ultraviolet, ozone, low temperature ozone, salt water and acid rain, a series of environmental accelerated aging tests were conducted to investigate the aging characteristics. From the test results, it was clarified that the thermal oxidation is the dominant degradation factor, which hardens the rubbers and results in a significant drop of performance. This study is fundamental to predicting the lifecycle of NR isolation bearings.

Phenothiazine as an Antifatigue Agent for Natural Rubber, Synthetic Polyisoprene and SBR

1965 ◽  
Vol 38 (3) ◽  
pp. 661-665
Author(s):  
Z. N. Tarasova ◽  
I. I. Eitingon ◽  
L. G. Senatorskaya ◽  
T. V. Fedorova ◽  
B. A. Dogadkin
Keyword(s):  
Mechanical Properties ◽  
Synergistic Effect ◽  
Natural Rubber ◽  
Thermal Oxidation ◽  
Fatigue Resistance

Abstract Phenothiazine has no effect on vulcanization of rubber or standard mechanical properties of the vulcanizates. Phenothiazine considerably increases fatigue resistance of vulcanizates of the rubbers studied, under different fatigue conditions. Under the effect of thermal oxidation and repeated deformation phenothiazine or its conversion products combine with the vulcanizate. The phenothiazine does not combine when subjected only to heating. When used with certain inhibitors of oxidation phenothiazine has a synergistic effect.

Study on Dehydration Process of Wet Natural Rubber by Single Screw Dehydrator and Properties of Dry Natural Rubber

2011 ◽  
Vol 418-420 ◽  
pp. 544-547
Author(s):  
Mei Chen ◽  
Fu Quan Zhang ◽  
Yong Zhou Wang ◽  
Mao Fang Huang ◽  
Wei Yong Deng
Keyword(s):  
Natural Rubber ◽  
Thermal Oxidation ◽  
Hammer Mill ◽  
Dehydration Process ◽  
Hot Air Drying ◽  
Single Screw ◽  
Hot Air ◽  
Unit Value ◽  
Better Than ◽  
Dehydration Effect

In this work, one self-invented closed single screw dehydrator was used to dehydrate wet natural rubber, instead of current three opened crepers and one hammer mill at home and abroad. The dehydration technology and the properties of the obtained dry natural rubber were studied. The results show that single screw dehydrator can simplify dehydration process. The water consumption of single screw dehydrator is 20% of current productive technology, meaning a lower wastewater discharge and treatment cost of wastewater. The moisture content of dehydrated natural rubber is lower than 20%, a good dehydration effect. The dry natural rubber dehydrated with single screw dehydrator has an improved thermal-oxidation ageing resistance whether dried by hot-air or microwave. The thermal-oxidation ageing resistance of natural rubber dried by microwave is better than that of hot-air drying, the value of initial plasticity (P0) and plasticity retention index (PRI) are 29.3 unit value and 19.26 unit value greater than that of SCR5 in GB/T 8081, respectively.

scholarly journals Influence of Low Temperature-Grown GaAs on Lateral Thermal Oxidation of Al0.98Ga0.02As

2000 ◽  
Vol 623 ◽  
Author(s):  
J. C. Ferrer ◽  
Z. Liliental-Weber ◽  
H. Reese ◽  
Y.J. Chiu ◽  
E. Hu
Keyword(s):  
Low Temperature ◽  
Thermal Oxidation ◽  
Oxidation Process ◽  
Gaas Layer ◽  
Transmission Electron ◽  
Low Temperature Gaas ◽  
Reference Samples ◽  
Thermal Oxidation Process ◽  
Low Temperature Grown Gaas

AbstractThe lateral thermal oxidation process of Al0.98Ga0.02As layers has been studied by transmission electron microscopy. Growing a low-temperature GaAs layer below the Al0.98Ga0.02As has been shown to result in better quality of the oxide/GaAs interfaces compared to reference samples. While the later have As precipitation above and below the oxide layer and roughness and voids at the oxide/GaAs interface, the structures with low-temperature have less As precipitation and develop interfaces without voids. These results are explained in terms of the diffusion of the As toward the low temperature layer. The effect of the addition of a Si02 cap layer is also discussed.

Oxidation of polyethylene under irradiation at low temperature and low dose rate. Part II. Low temperature thermal oxidation

2006 ◽  
Vol 91 (7) ◽  
pp. 1598-1605 ◽  
Author(s):  
N. Khelidj ◽  
X. Colin ◽  
L. Audouin ◽  
J. Verdu ◽  
C. Monchy-Leroy ◽  
...  
Keyword(s):  
Low Temperature ◽  
Dose Rate ◽  
Thermal Oxidation ◽  
Low Dose ◽  
Low Dose Rate

Hydroperoxide Formation and Thermal Oxidation of Methyl tert-Butyl Ether Oxidation at Low Temperature

2019 ◽  
Vol 33 (12) ◽  
pp. 12894-12904 ◽  
Author(s):  
Qiang Zhang ◽  
Mieko Kumasaki ◽  
Xiongmin Liu ◽  
Fan Ren ◽  
Yosuke Nishiwaki ◽  
...  
Keyword(s):  
Low Temperature ◽  
Thermal Oxidation ◽  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Tert Butyl ◽  
Hydroperoxide Formation

Tire Black Sidewall Surface Discoloration and Non-Staining Technology: A Review

1998 ◽  
Vol 71 (3) ◽  
pp. 590-618 ◽  
Author(s):  
Walter H. Waddell
Keyword(s):  
Fatigue Life ◽  
Natural Rubber ◽  
Outer Surface ◽  
Chain Scission ◽  
Butadiene Rubber ◽  
Ethylene Propylene ◽  
Polymer Decomposition ◽  
Sidewall Surface

Abstract The tire black sidewall is the outer surface that protects the casing against weathering. It is formulated for resistance to weathering, ozone aging, abrasion, tearing and cracking, and for good fatigue life by using blends of natural rubber and cis-butadiene rubber. Protection against ozone aging is of particular interest since reaction with these olefinically unsaturated elastomers results in polymer decomposition via chain scission. Use of N-alkyl, N′-aryl-para-phenylenediamine antiozonants has proved most effective. However, their use also results in a surface discoloration, and thus they can be used in only limited amounts when tire appearance is also an important factor. A review is made of the literature describing this surface discoloration problem and approaches to formulate a black sidewall compound to eliminate this surface discoloration upon exposure to ozone. Methods include use of non-staining antiozonants, and uses of elastomers with saturated backbones such as ethylene-propylene-diene terpolymers, halobutyl rubbers and brominated-isobutylene- co-para-methylstyrene.

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