Ethylene-propylene-diene monomer properties

TPEs from blends of rubber and plastics constitute an important category of TPEs. These can be prepared either by the melt mixing of plastics and rubbers in an internal mixer or by solvent casting from a suitable solvent. The commonly used plastics and rubbers include polypropylene (PP), polyethylene (PE), polystyrene (PS), nylon, ethylene propylene diene monomer rubber (EPDM), natural rubber (NR), butyl rubber, nitrile rubber, etc. TPEs from blends of rubbers and plastics have certain typical advantages over the other TPEs. In this case, the required properties can easily be achieved by the proper selection of rubbers and plastics and by the proper change in their ratios. The overall performance of the resultant TPEs can be improved by changing the phase structure and crystallinity of plastics and also by the proper incorporation of suitable fillers, crosslinkers, and interfacial agents. 

This is a nonpolar rubber with very little unsamration. Nanoclays as well as nanotubes have been used to prepare nanocomposites of ethylene-propylene-diene monomer (EPDM) rubber. The work mostly covers the preparation and characterization of these nanocomposites. Different processing conditions, morphology, and mechanical properties have been smdied [61-64]. Acharya et al. [61] have prepared and characterized the EPDM-based organo-nanoclay composites by X-ray diffracto-gram (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy... 

Mechanical Properties and Cure Rate Index of the Mixes—Role of Dry Bonding System on the Reinforcement of Ethylene-Propylene-Diene Monomer (EPDM) Rubber with Melamine Fiber ... 

Radiation Treatment NVP, 2-hydroxyethylmethacrylate (HEMA), and acrylamide (AAm) have been grafted to the surface of ethylene-propylene-diene monomer (EPDM) rubber vulcanizates using the radiation method (from a Co 7 source) to alter surface properties such as wettability and therefore biocompatibility [197]. Poncin-Epaillard et al. [198] have reported the modification of isotactic PP surface by EB and grafting of AA onto the activated polymer. Radiation-induced grafting of acrylamide onto PE is very important... 

The ductility of GRT-polyethylene blends drastically decreases at ground rubber concentration in excess of 5%. The inclusion of hnely ground nitrile rubber from waste printing rollers into polyvinyl chloride (PVC) caused an increase in the impact properties of the thermoplastic matrix [76]. Addition of rubber powder that is physically modihed by ultrasonic treatment leads to PP-waste ethylene-propylene-diene monomer (EPDM) powder blends with improved morphology and mechanical properties [77]. 

With larger amount of propylene a random copolymer known as ethylene-propylene-monomer (EPM) copolymer is formed, which is a useful elastomer with easy processability and improved optical properties.208,449 Copolymerization of ethylene and propylene with a nonconjugated diene [EPDM or ethylene-propylene-diene-monomer copolymer] introduces unsaturation into the polymer structure, allowing the further improvement of physical properties by crosslinking (sulfur vulcanization) 443,450 Only three dienes are employed commercially in EPDM manufacture dicyclopentadiene, 1,4-hexadiene, and the most extensively used 5-ethylidene-2-norbomene. 

Bhowmick and co-workers [168] investigated the bulk and surface modification of ethylene propylene diene monomer (EPDM) rubber and fluoro-elastomer by electron beam irradiation. The structure of the modified elastomers was analysed with the help of IR spectroscopy and XPS. The gel content, surface energy, friction coefficient and dynamic mechanical properties of bulk modified fluoro-elastomers and the surface-modified EPDMs were also measured. The resultant properties of the modified EPDM were correlated with the structural alterations. 

The elastomeric sealing components of the metering valve are particularly critical. In those valves used with CFC propellants, the elastomeric seals have typically been formed from an acrylonitrile/butadiene rubber, which has been cured with sulfur. These rubber seals may not be fully compatible with HFA propellants hence, alternative elastomeric materials have been used. These materials include peroxide-cured acrylonitrile/ butadiene, ethylene-propylene diene monomer (EPDM), and chloroprene and thermoplastic elastomers (TPE). The elastomeric materials used to form the dynamic seals around the stem and the static gasket seal between the can and valve may differ based on the required properties of the rubber for the specific function of the seal. The most important characteristics of the elastomeric seals... 

When ethylene is copolymerized with substantial amounts (>25%) of propylene an elastomeric copolymer is produced, commonly known as ethylene-propylene rubber (EPR) or ethylene-propylene monomer (EPM) rubber. When a diene, such as dicyclopentadiene, is also included, a terpolymer known as ethylene-propylene-diene monomer (EPDM) rubber is obtained. EPR and EPDM are produced with single site and Ziegler-Natta catalysts and are important in the automotive and construction industries. However, EPR and EPDM are produced in much smaller quantities relative to polyethylene. Elastomers display vastly different properties than other versions of industrial polyethylene and are considered outside the purview of this text. EPR and EPDM will not be discussed further. 

Recently there has been considerable work on metal-neutralized sulfonated elastomers (23,24,25). The effect of various monovalent and divalent cations on physical properties of sulfonated ethylene-propylene-diene monomers (EPDM s) has been investigated and large differences have been found in both melt-flow rates and tensile properties, depending on the cation used. 

Ethylene-Propylene-Diene-Monomer (EPDM) Rubber. The main properties of EPDM are its outstanding heat, ozone and weather resistance, as well as its electrical insulating properties. EPDM rubber finds use in vehicles (weather seals in windows and trunks, cooling system hoses), in safety equipment (seals in respirators), roofing (waterproofing of roofs), and playground surfacing. 

Blends of PET/HDPE have been treated previously in the literature [157, 158]. These are immiscible, but the addition of compatibilizers improves the mechanical properties of the blend, such as styrene-ethylene/butylene-styrene (SEBS) and ethylene propylene diene monomer (EPDM) [157], MAH [158], Poly(ethylene-stat-glycidyl metha-crylate)-graft-poly(acrilonitrile-stat-styrene) (EGMA), poly (ethylene acrylic acid), and maleated copolymers of SEBS, HDPE, ethylene-propylene copolymer (EP). The addition of compatibilizers modifies the rheological properties of blends of PET with HDPE, in such a way that increases in viscosity are observed as the component interactions augment. Changes in crystallization of PET were evaluated in blends with Polyphenylene sulfide (PPS), PMMA, HDPE aromatic polyamides, and copolyesters [159]. 

RUT Rutherford, S.W., Kurtz, R.E., Smith, M.G., Honnell, K.G., and Coons, J.E., Measurement and correlation of sorption and transport properties of ethylene-propylene-diene monomer (EPDM) elastomers, J. Membrane Sci., 263, 57, 2005. 

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. 

Over the years, much of the research on accelerated-sulfur vulcanization was done by using natural rubber as a model substrate. Natural rubber was the first elastomer and therefore the search for the understanding of vulcanization originated with work on natural rubber. Most of the work cited in the previous sections is related to natural rubber. However, some rather early studies have been directed to the vulcanization of butadiene 1,4-polymers (Skinner and Watson, 1969 Wolfe et al, 1329 Gregg and Katrenick, 1970). More recent is the work of Pellicioli and coworkers. Early basic work on the vulcanization of ethylene-propylene-diene-monomer rubber (EPDM) has been carried out (van den Berg et al., 1984a,b). Recently, Kuno and coworkers did basic work on EPDM networks. They found that, essentially, the vulcanizate properties depend only on the crosslink density, not on the type of curing system (Dijkhuis et al., 2009). 

Studies by Ravikumar et al. (2005) show that PTT/ethylene propylene diene monomer (EPDM) blends are irrmriscible, which is supported by an increase in the free volume and constancy in crystallinity of PTT with increasing EPDM content and the use of ethylene propylene monomer grafted maleic anhydride as compatibilizer is found to produce significant improvement in properties by modifying the interface of the blends. 

Zhao, R. and Dai, C. 2002. Mechanical property and morphology comparison between the two blends poly (propylene)/ ethylene-propylene-diene monomer elastomer and poly(propylene)/ maleic anhydride-g-ethylene-propylene-diene monomer, lournal of Avvlied Polymer Science 86 2486-2491. 

Pasbakhsh, R, Ismail, FI., Ahmad Fauzi, M. N., and Abu Bakar, A. 2009. Influence of maleic anhydride grafted ethylene propylene diene monomer (MAH-g-EPDM) on the properties of EPDM nanocomposites reinforced by halloysite nanotubes. Polymer Testing 28 548-559. 

Electron beam modification of PTFE nanopowder resulted in increasing concentration of radicals and carboxyhc groups (—COO H) with increase in irradiation dose. Low-temperature reactive mixing of the modified PTFE with ethylene-propylene-diene-monomer (EPDM) rubber produced PTFE coupled EPDM rubber compounds with the desired physical properties due to the formation of a compatible interphase this was confirmed by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) [56]. 

Use of nanoparticles as fillers in mbbers is highly relevant because end use applications of rubber compounds require filler reinforcement. Most of the literature on rubber nanocomposites is based on the use of nanoclay as the filler. It has been shown that incorporation of nanoclay in synthetic rubbers, like styrene butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), ethylene propylene diene monomer (EPDM) mbber etc. enhances the mechanical, anti-ageing and barrier properties. 

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