Sulfur-Cure-Compatible Blends of Halogenated Ethylene-Propylene Copolymers and Diene Rubbers

1976 ◽  
Vol 49 (2) ◽  
pp. 353-366 ◽  
Author(s):  
R. T. Morrissey
Keyword(s):  
Natural Rubber ◽  
Uv Light ◽  
Metal Halide ◽  
High State ◽  
Adhesive Properties ◽  
Economical Method ◽  
Ethylene Propylene ◽  
Good Adhesive ◽  
Diene Rubbers

Abstract The chlorination of ethylene-propylene copolymers represents a possible economical method of producing a sulfur-curable EPM polymer. There are many feasible uses for these polymers. However, their incompatibility of cure with the more generally used polymers such as SBR, cis-polybutadiene, and natural rubber has limited their use, particularly in blends. It has been found that this can be overcome by halogenation of the EPM in the presence of certain catalysts. Earlier studies of Crespi and Bruzzone have shown that dehydrochlorina tion must follow chlorination for the polymer to show a high state of cure and good rebound characteristics. It has been discovered that the presence of certain metal halide catalysts and uv light tend to promote not only the halogenation of the EPM but also the dehydrohalogenation process. Further modification of the chlorinated and brominated EPM can be produced by halogenating in two steps. The resulting halogenated EPM shows good cure compatibility with highly unsaturated polymers, such as natural rubber. The halogenated copolymers show good adhesive properties to blends of diene polymers and have been used as adhesives between EPDM and fabric.

Halogenation of Ethylene Propylene Diene Rubbers

1971 ◽  
Vol 44 (4) ◽  
pp. 1025-1042 ◽  
Author(s):  
R. T. Morrissey
Keyword(s):  
Natural Rubber ◽  
Double Bonds ◽  
Optimum Amount ◽  
Ethylene Propylene ◽  
Rubber Compounds ◽  
Rubber Part ◽  
Curing Agents ◽  
Diene Rubbers ◽  
Curing Systems

Abstract The ethylene propylene diene rubbers (EPDM) have been modified by halogenation. The reaction has been considered as one mainly of addition to the double bonds of the diene portion of the rubber. Dehydrohalogenation may occur to varying degrees, depending on the conditions of the reaction and the diene present in the rubber. Part of the halogen is believed to be in the allylic position. The halogenated EPDM may be vulcanized by sulfur as well as many of the curing agents used for other halogen-containing polymers. Both types of curing systems can function in the same compound. Therefore, the halogenated EPDM rubbers can be covulcanized with the highly unsaturated elastomers such as natural rubber, cis polybutadiene, and the SBR rubbers. The excellent properties, resistance to ozone, and flexing, of the halogenated EPDM can be imparted to these elastomers using standard curing systems. Also, the uncured tack of halogenated EPDM can be improved by increasing amounts of natural rubber. In addition, other advantages are adhesion of these blends to other rubber compounds and metal. It has been shown that the cure compatibility properties of the halogenated EPDM can be varied as the halogen is increased in the rubber. Evidence has been presented which shows there is an optimum amount of halogen necessary for the best properties in mixtures with other elastomers.

Dynamic Testing of Automotive Rubber Parts by the Resonant Beam Tester. Effect of Polymer, Deflection, Age, and Temperature on Dynamic Rate

1964 ◽  
Vol 37 (4) ◽  
pp. 866-877 ◽  
Author(s):  
M. Lowman ◽  
H. E. Keller
Keyword(s):  
Natural Rubber ◽  
Room Temperature ◽  
Dynamic Testing ◽  
Effect Of Temperature ◽  
Ethylene Propylene ◽  
Rate Decrease ◽  
Resonant Beam

Abstract When the recipe is basically the same, different polymers differ in dynamic rate and damping. Ethylene—propylene terpolymer, SBR, neoprene, and butyl gave higher dynamic rate and higher damping than natural rubber, polyisoprene, and the blend of polyisoprene and cis 1,4-polybutadiene. The lowest dynamic rate and lowest damping is obtained with polyisoprene. At room temperature, polymers having the highest damping also have the largest ratio of dynamic to static rate. One cannot predict the effect of temperature on dynamic rate by measuring static rate at these temperatures. Increase in temperature lowers dynamic rate, decrease in temperature increases it. This effect was least with a blend of polyisoprene and cis 1,4-polybutadiene, closely followed by polyisoprene, and natural rubber. The largest change was with butyl. Dynamic rate increases with time after cure. After 26 hr, dynamic rate is a function of the logarithm of time. This effect is least with polyisoprene. Natural rubber, SBR, EPT, neoprene and a blend of polyisoprene with cis 1,4-polybutadiene all follow Equation (1). Butyl has, by far, the greatest change in dynamic rate with time. Reducing the deflection from 0.012 in. to 0.004 in. linearly increased the dynamic rate. Times of vibration between 2 minutes and 60 minutes at room temperature had no effect on dynamic rate.

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.

Sign in / Sign up

Export Citation Format

Share Document