ETHYLIDENE NORBORNENE TERPOLYMER

Recent studies in our laboratories have been concerned with the physical properties of sulfonated ionomers such as sulfonate ethylene/propylene/ethylidene norbornene terpolymers (4, or lightly sulfonated polystyrene (S-PS) (11). These ionomers exhibit pronounced ion pair association (at sulfonate levels > 15 milli-equivalents/100 g polymer) to a degree that they appear crosslinked covalently. These interactions can be dissipated by the addition of a polar additive, thereby showing that such associations are indeed physical and do not arise due to covalent crosslinking. 

Luminescence of mercaptoanthracene tagged ethylene/propylene/ ethylidene norbornene terpolymer irradiated with x-rays at 90 K to a dose of... 

Figure 6, Transmission electron micrograph of OsO stained blend of 50 wt % PBD and 50 wt % ethylene/propylene/ethylidene norbornene terpolymer. Magnification, 3300X,...

Chem. Descrip. Ethylene-propylene-ethylidene norbornene terpolymer CAS 25038-36-2... 

An EPDM (ethylene-propylene-ethylidene norbornene terpolymer) rubber was dissolved in o-dichlorobenzene with 1 phr of carbon-60. When cast onto a glass slide and dried, an insoluble film exhibiting reversible elasticity forms. 8 refs. 

EPDMs are utilized in the automobile industry for their heat resistance, ozone resistance, and overall stability. Several key characteristics that are useful to the automotive chemist can be derived from the structure. Figure 8.8 shows the straight chain backbone of the EPDM polymer. EPDM is a terpolymer, or three-monomer polymer, consisting of propylene, ethylene, and another constituent—in this case, ENB (ethylidene norbornene). 

Finally, it is worth mentioning the first example of a study of the effect of diene on C2-C3 analysis by IR (80). It refers to ethylidene norbornene (ENB), but the procedure is of general applicability. A correction coefficient K on the results obtained through the near-IR method (8) was obtained by analyzing a set of terpolymers with 14C-labelled C2 and subtracting13 from the measured C3 content an amount proportional to the diene concentration. K was evaluated so as to minimize the sum of the squares of the differences (total found —100), where total found stands for the sum C2 (determined by radiochemical analysis) + diene (determined by IR) + C3 (determined by near-IR and suitably corrected for the diene influence). In other words, the expression to minimize is... 

Ethylene/propylene/dicyclopentadiene terpolymer Ethylene-propylene-ethylidene norbornene elastomer, adhesives Epichlorohydrin elastomer Epichlorohydrin/ethylene oxide/allyl glycidyl ether terpolymer Epichlorohydrin/ethylene oxide copolymer Polyisoprene Polyurethane, thermoplastic... 

Ethylene propylene diene terpolymers (EPDM) can be used to improve the ozone resistance of bromobutyl/natural rubber binary polymer blends, eliminating the need for chemical antiozonants. Addition of 10 phr of EPDM (with a high ethylidene norbornene, ENB, content of9%) to a 50/50 bromobutyl rubber/natural rubber blend results in a compound vdth good static and dynamic ozone resistance. EPDM with a 5.7% ENB level is another suggested grade of polymer. 

Altenau and co-workers [111] applied time-averaging NMR to the determination of low percentages of termonomers such as 1,4-hexadiene, dicyclopentadiene and ethylidene norbornene in ethylene-propylene termonomers. They compared results obtained by NMR and the iodine monochloride procedure of Lee and co-workers [81]. The chemical shifts and splitting pattern of the olefinic response were used to identify the termonomer. Figure 3.11 shows the time-averaged NMR spectra of ethylene-propylene terpolymers containing various dienes. 

DMTA together with other techniques such as DSC have been used in morphological studies on a variety of polymers including epoxy-polyaniline resin [53], ethylene-propylene 5-ethylidene-2-norbornene terpolymer-polyaniline blends [54], Nylon 6-ethylene vinyl alcohol blends [55], polyoxymethylene [56], ethylene-propylene-... 

Other applications of AFM to the characterisation of polymers include polythiophene [9], nitrile rubbers [10], perfluoro copolymers of cyclic polyisocyanurates of hexamethylene diisocyanate and isophorone diisocyanate [11], perfluorosulfonate [12], vinyl polymers [13], polyhydroxybutyrate [14], polyacrylic acid nanogels [15], acrylic copolymers [16, 17], polyurethanes [18, 19], ethylene methacrylate copolymer [4, 20], polyamides [21], polyvinyl pyrrolidone [22], and polyethyl methacrylate dispersions [23], acryloyl chloride [13], aniline-4-sulfonic acid [24], ethylene propylene 5-ethylidene-2-norbornene terpolymer [25] and butylene adipate - butylene terephthalae [26]. 

Polymers containing unsaturated side-groups such as terpolymers, ethylene-co-propylene-co-ethylidene norbornene (7.3) and ethylene-co-propylene-co-dicyclopentadiene (7.4) react almost quantitative with singlet oxygen ( O2), giving the following polymeric hydroperoxides [574, 607, 2291] ... 

When xenon is adsorbed, for example, into a solid EPDM rubber (a terpolymer composed of ethylene, propylene and ethylidene norbornene) at least four distinct Xe resonance signals can be observed indicating the presence of physically distinct domains the intensity ratios may be used for the determination of the size of the domains, whereas the shielding differences reveal the variation of the destiny in the domains. When the rubber is cross-linked, the spectrum is clearly different from the one before... 

Commercial grades of ethylene-propylene copolymers (EPR) contain 60-75 mol% of ethylene to minimize crystallization. The addition of a third monomer, such as 1,4-hexadiene, dicyclopentadiene, or 5-ethylidene-2-norbornene, produces generally amorphous faster-curing elastomers. A large number of such terpolymers, referred to as EPDM, is available commercially. Their properties, performance, and response to radiation vary considerably depending on macrostructure, ethylene/propylene ratio, as well as on the type, amount, and distribution of the third monomer. 

On-line SEC-NMR has successfully applied to the determination of chemical composition distribution in ethylene-propylene-diene terpolymers (EPDM) by the use of H-NMR at 750 MHz [24], EPDM containing 2-ethylidene-5-norbornene (ENB), as a diene... 

Scheme 16.36. Polymerization and structure of ethylene/ propene/diene terpolymer (EPDM), with 5-ethylidene-2-norbornene (ENB) given as an example for the diene.

EPDM is a terpolymer produced from ethylene, propylene, and a diene monomer that is usually 5-ethylidene-2-norbornene (ENB), see Eigure 3.12. Good EPDM properties are attainable because the stereospecific Ziegler-Natta catalysts and the newer metallocene-type catalysts are used in the polymerization of these elastomers. Much proprietary knowledge is applied with the latest catalysts to help the EPDM producers achieve a competitive advantage in the marketplace. Today, about 20% of all EPDM goes into the production of TPOs (thermoplastic olefins) or TPVs (thermoplastic vulcanizates), mainly for nontire automobile uses. (About 13% of EPDM production is used in TPO manufacture while about 7% is consumed in TPV production.)... 

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