Evaluation of Crosslinking Coagents in Ethylene-Propylene Rubber

Abstract Ethylene-propylene rubber (EPR), a saturated elastomer, is usually vulcanized by a peroxide-sulfur curing system. However, several disadvantages associated with this system—undesirable odor for some applications, narrow curing range, and poor strength obtained with mineral fillers—emphasize the need for other reactive chemicals as crosslinking coagents for EPR. Certain polyfunctional monomers such as ethylene dimethacrylate, and polyfunctional polymers such as 1,2-polybutadiene were promising crosslinking coagents for EPR. When used in place of sulfur, they decrease peroxide requirements of moderately filled EPR compounds. They also impart higher states of cure, improve the cure cycle, and decrease odor. The coagents are much superior to sulfur in mineral-filled EPR compounds where, in addition to increasing the crosslinking efficiency, they also improve the wetting of the filler particles by the rubber. However, in highly loaded (carbon black and oil) EPR formulations, the superiority of the peroxide-coagent system is mainly due to the ability to replace sulfur and, consequently, to improve odor.

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Electrical and mechanical properties of carbon black filled ethylene propylene rubber during thermal oxidation aging

53rd Electronic Components and Technology Conference, 2003. Proceedings. ◽

10.1109/ectc.2003.1216520 ◽

2004 ◽

Author(s):

Yangyang Sun ◽

Shijian Luo ◽

C.P. Wong

Keyword(s):

Mechanical Properties ◽

Carbon Black ◽

Thermal Oxidation ◽

Ethylene Propylene ◽

Ethylene Propylene Rubber

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New Vulcanizing Agents for Ethylene-Propylene Elastomers. II

Rubber Chemistry and Technology ◽

10.5254/1.3539968 ◽

1962 ◽

Vol 35 (4) ◽

pp. 1091-1100

Author(s):

Peter E. Wei ◽

John Rehner

Keyword(s):

Zinc Oxide ◽

Iron Oxide ◽

Carbon Black ◽

Periodic System ◽

Chemical Diversity ◽

Complex Behavior ◽

Iron Compounds ◽

Ethylene Propylene ◽

Ethylene Propylene Rubber

Abstract In searching for new vulcanizing systems for ethylene-propylene elastomers, we have found several more classes of active agents, heretofore undisclosed. They are: (a) perhaloalkanes and some polyhaloalkanes; (b) polyhalocycloalkenes; and (c) poly-N-halobenzoguanamines. Specific examples are: hexachloroethane, octachloropropane, octachlorocyclopentene, perchlorofulvalene, and N,N,N′,N′-tetrachlorobenzoguanamine. These agents are all effective in ethylene-propylene rubber, and some are capable of vulcanizing polyethylene, polypropylene, polyisobutylene, butyl, and highly unsaturated rubbers and their blends. The agents are most effective in the presence of sulfur. All are active in carbon black stocks, and at least some are active in mineral-filled and oil-extended stocks. Some of the vulcanizing agents can be accelerated by certain oxides and salts of metals widely distributed over the periodic system. Among the most active accelerators are iron compounds, such as iron tallate, stearate, naphthenate, octoate, and oxalate, and corresponding combinations of iron oxide and the free acids. These accelerators are antagonized by the presence of zinc oxide. The chemical diversity of these classes of vulcanizing agents and the complex behavior of the accelerators mentioned preclude an explanation of the vulcanization chemistry at this time.

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Electrical Conductivity of Polystyrene-Rubber Blends Loaded with Carbon Black

Rubber Chemistry and Technology ◽

10.5254/1.3538419 ◽

1997 ◽

Vol 70 (1) ◽

pp. 60-70 ◽

Cited By ~ 33

Author(s):

B. G. Soares ◽

F. Gubbels ◽

R. Jéro^me ◽

E. Vanlathem ◽

R. Deltour

Keyword(s):

Electrical Conductivity ◽

Carbon Black ◽

Percolation Threshold ◽

Chemical Structure ◽

Two Phase ◽

Ethylene Propylene ◽

Rubber Blends ◽

Ethylene Propylene Rubber

Abstract Polystyrene/rubber blends have been loaded with carbon black (CB) and the filler localization in the two-phase polyblends has been studied in relation to the chemical structure of the rubber. The CB localization and the electrical conductivity are greatly influenced by the substitution of the rubber chains. In polystyrene/polybutadiene blends, the filler is localized within the polybutadiene phase. In contrast, in polystyrene/polyisoprene and polystyrene/ethylene—propylene rubber (EPM) blends, CB is mainly localized at the interface, so that the CB percolation threshold in cocontinuous two-phase polyblends is dramatically decreased.

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