Ethylene-propylene-diene monomer strength

FIGURE 31.9 Change in the peel strength and radiation dose of ethylene-propylene-diene monomer (EPDM)/EPDM joint [Eo/y Eo/yl EPDM/natural mbber (NR)/EPDM joint [Eo/y NR Eo/yl and EPDM/Al joint [Eo/y Al]. (From Sen Majumder, P. and Bhowmick, A.K., in Polymer Surface Modification Relevance to Adhesion, Vol. It, Mittal, K.L., Ed., VSP, Utrecht, The Netherlands, 2000,425. With permission.)... 

A blend of low-density polyethylene (LDPE) polyethylene (LDPE) with the terpolymer ethylene-propylene-diene monomer rubber (EPDM) exhibits a synergistic effect on tensile strength if EPDM is partially crystalline, but a nonsynergistic effect if the EPDM is amorphous [65]. This example shows the dramatic effect that morphology can have on properties of polymer blends. The synergism apparently arises from a tendency for crystallites in the LDPE to nucleate crystalli2ation of ethylene segments in the EPDM. 

A process has been developed for electroplating a PPA resin, modified with ethylene propylene diene monomer rubber, ethylene-propylene rubber, and styrene-butadiene rubber. As etching solution, chromic acid is used. However, it has been found that the concentration of Cr + is crucial for the success of the method. The concentration of Cr + is in the range of 50-55 gU Low levels of Cr + result in poor adhesion of the final metal plating, while high levels of Cr + can cause the formation of small blisters in the metal plating. The influence of the process parameters on the peel strength is shown in Table 12.9. 

TPO materials are defined as compounds (mixtures) of various polyolefin polymers, semicrystalline thermoplastics, and amorphous elastomers. Most TPOs are composed of polypropylene and a copolymer of ethylene and propylene called ethylene—propylene rubber (EPR) [2]. A common rubber of this type is called ethylene propylene diene monomer rubber (EPDM), which has a small amount of a third monomer, a diene (two carbon-carbon double bonds in it). The diene monomer leaves a small amount of unsaturation in the polymer chain that can be used for sulfur cross-linking. Like most TPEs, TPO products are composed of hard and soft segments. TPO compounds include fillers, reinforcements, lubricants, heat stabilizers, antioxidants, UV stabilizers, colorants, and processing aids. They are characterized by high impact strength, low density, and good chemical resistance they are used when durability and reliability are primary concerns. 

Ramar and Alagar [31] compared the dielectric strengths of nanoclay reinforced blends of ethylene-propylene-diene monomer grafted with fris(2-methoxyethoxy)vinylsilane (EPDM-g-TMEVS) and EPDM-g-TMEVS/PMMA blends. The values of dielectric strength, volume resistivity, surface resistivity and arc resistance were all increased with increasing concentration of EPDM-g-TMEVS because of the presence of Si-O-Si linkages. The blends filled with nanoclay showed improved dielectric properties because of the presence of the inorganic moiety. 

Ethylene propylene diene monomer (EPDM) modifiers are used in thermoplastic olefins for automotive bumpers and parts as well as scattered consumer durable products. Maleic anhydride-grafted EPDM reacts with the matrix resin, typically nylon, to become its own compatibilizer. This type of modifier provides for excellent balance in impact, hardness, modulus, and tensile strength, and it is the major additive component of super tough nylon. (See also ethylene propylene diene monomer.)... 

Base rubbers may be based on silicone, fluoropolymers, or hydrocarbons. Although silicone rubbers such as silicone S and G have been applied in stacks, it has become clear that they are not sufficiently stable [83-85]. Materials like ethylene-propylene-diene-monomer (EPDM), butyl rubber (IRR), or fluororubbers (FKM such as Viton )seem better suited. Further research is carried out to optimize properties like hardness, tensile strength, and stress relaxation. Also the morphology is being considered, with apparently a preference for profiled over flat gaskets. 

Maleinized polybutadiene has demonstrated particularly favourable effects for filled elastomers, improving the tensile strength, tear strength and modulus of a sulphur cured EPDM (ethylene propylene diene monomer rubber) containing 100 phr filler, while a stearic acid coating actually caused all these properties to deteriorate significantly. 

Thermoplastic polyolefins (TPOs) are composite blends of semicrystalline polypropylene and ethylene propylene copolymer (EPR) or ethylene propylene diene monomer (EPDM), widely used in the automotive industry for the production of plastic car parts such as bumper fascia [1]. Polypropylene, which is the major component in such blends, is an inexpensive, easily proccessible polymer, although its poor mechanical properties necessitate the addition of a rubber-dispersed phase. The added rubber acts as an impact modifier by imparting improved ductility, crack resistance, and impact strength to the resulting TPO [1-4]. The cost-effectiveness, light weight, processability, and resilience of TPOs have made them increasingly viable alternatives to steel for bumpers and other car parts. 

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