Ethylene-propylene-diene materials

Ethylene-Propylene and Ethylene-Propylene-Diene Materials... 

The environmental and material tests showed that neoprene is the best gasket material for mortar metal/plastic ammunition containers. Styrene butadiene rubber and natural rubber (60) were discontinued from the environmental testing because of their poor performance in material tests (heat, oil, and grease). The ethylene propylene diene material did not perform well in drop test and leak test. 

At this point in the process, thermoplastic and chlorosulfonated polyethylene (CSPE) membranes are complete and are ready for packaging. In the case of ethylene—propylene—diene monomer (EPDM), the curing step occurs before the membrane is ready for packaging. The curing process is accomphshed by placing the membrane in a large vulcanizer where the material is heated under pressure to complete the cure. 

Initial materials of this super-tough type were blends of nylon 66 with an ionomer resin (see Chapter 11). More recent materials are understood to be blends of nylon 66 with a modified ethylene-propylene-diene terpolymer rubber (EPDM rubber—also see Chapter 11). One such modification involves treatment of the rubber with maleic anhydride, this reacting by a Diels—Alder or other... 

Proper selection of plastic matrix fire retardants and property enhancers offers acceptable combinations of impact properties and heat-distortion temperature (HDT) values for fire retardant plastics. This can be demonstrated by fire retardant styrenics. Fire retardant enhancers have special interest as property enhancers for example the addition of a highly flammable material such as ethylene propylene diene terpolyer (EPDM), dramatically improves the bromine efficiency of octabromodiphenyl oxide in ABS by increasing char-forming without changing the Sb-Br reaction. 

ISO 6402-1 2002 Plastics - Acrylonitrile-styrene-acrylate (ASA), acrylonitrile-(ethylene-propylene-diene)-styrene (AEPDS) and acrylonitrile-(chlorinated polyethylene)-styrene (ACS) moulding and extrusion materials - Part 1 Designation system and basis for... 

Tires, natural mbber tubes, and butyl tubes are the main sources of scrap and reclaim (see Elastomers, synthetic-polyisoprene). Specialty reclaim materials are made from scrap silicone, chloroprene (CR), nitrile— butadiene (NBR), and ethylene—propylene—diene—terpolymer (EPDM) mbber scraps (see... 

Rao, S.S., and Ninan, K.N. (2002) Ethylene- propylene-diene monomer (EPDM)-neoprene rubber blends evaluation as rocket motor insulation material. Proc. MACRO Inti Seminar, Dec. 09-11, 2002, Kharagpur,... 

At room temperature, PE is a semi-crystalline plastomer (a plastic which on stretching shows elongation like an elastomer), but on heating crystallites melt and the polymer passes through an elastomeric phase. Similarly, by hindering the crystallisation of PE (that is, by incorporating new chain elements), amorphous curable rubbery materials like ethylene propylene copolymer (EPM), ethylene propylene diene terpolymer (EPDM), ethylene-vinyl acetate copolymer (EVA), chlorinated polyethylene (CM), and chlorosulphonated polyethylene (CSM) can be prepared. 

Cyanoacrylates can be used to bond many materials, including most thermoplastics and even the more difficult ones like polyethylene, polypropylene, and ethylene-propylene-diene ( EPDM ) rubber. The best results are obtained with close contact and narrow bonds (some formulations have limited ability to bridge large or irregular gaps between the surfaces). 

Materials. The polymers used are commercial isotactic polypropylene (PP, Hercules, Profax 6523) and ethylene-propylene-diene terpoly-mer (EPDM, duPont, Nordel Hydrocarbon Rubber). Physical properties of the two polymers are listed below. 

Polypropylene, in particular, has a very low surface tension (less than 32 dynes/cm2). Because of the low surface tension, it is very difficult to wet out and because of the apolar nature of the polypropylene backbone, it is a very difficult material to adhere to. Therefore, copolymers of ethylene propylene diene monomers (EPDM) with polypropylene have been developed. The higher the level of... 

Copolymers of ethylene with a-olefins, such as the short-chain branched LLDPE (linear low-density polyethylene) impact materials or the EPD (ethylene-propylene-diene copolymer) rubbers represent major percentages of the total polyolefin production, due to their desirable mechanical properties. Solid-state MgCl2-supported Ziegler-Natta catalysts however, have unfavourable reactivity... 

The principal use of ethylene-propylene rubbers (ethylene-propylene-diene monomer (EPDM) or ethylene-propylene monomer (EPM) types) is in the manufacture of heat exchanger gaskets. When cured using peroxides, these materials can be used for extended periods at up to 150 °C. Normal conditions of service are high temperatures (<130 °C) and flow or static exposure to aqueous food. 

The elastomeric/polymeric or other material constituting the principal structure of the component (e.g., high-density polyethylene, ethylene-propylene-diene rubber, and stainless steel). 

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