Ethylene - propylene - diene terpolymers

Barroso-Bujans et al. [60] prepared nanocomposites of carbon nanotubes and sul-fonated ethylene-propylene-norbomene terpolymer and compared the mechanical properties of carbon nanotubes and carbon black ethylene-propylene-norborene composites. They also evaluated the effect of carbon nanotube dispersion on the mechanical, thermal, and electrical behavior. 

The curing process was analyzed by means of a rheometry test. The rheograms of ethylene-propylene-diene composites show that the maximum for a sample of sul-fonated ethylene-propylene-norbomene was three times higher than that for virgin ethylene-propylene-norbomene terpolymer. This result suggests that the incorporation of sulfonate groups onto the carbon nanotube surface reduces the cross-limiting efficiency of the benzoyl peroxide catalyst used in the preparation. 

It is well known that phenyl compounds interfere in the peroxide vulcanization by acting as radical traps and a consequent reduction in efficiency [61]. Nevertheless, it is worth noting that only a low percentage of benzene sulfonic groups (about 2%) is present in modified carbon nanotubes, which might indicate that other interactions are involved. 

The effect of the pristine and modified ethylene-propylene-norbomene vulcanization reaction was also analyzed by differential scanning calorimetry under dynamic conditions at different heating rates (from 2 to 50°C/min), where the curing temperature 

Loos et al. [62,63] studied the effect of carbon nanotube addition on the mechanical and thermal properties of epoxy components and matrices. 

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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... 

EPDM VYSTALON 3708 ESSO Ethylene-propylene-diene terpolymer... 

Han S.J., Lohse D.J., Radosz M., and Sperling L.H. Thermoplastic vulcanizates from isotactic olypro-pylene and ethylene-propylene-diene terpolymer in supercritical propane Synthesis and morphology. Macromolecules, 31, 5407, 1998. 

The most prevalent approach to achieve long-lasting and nonstaining ozone protection of rubber compounds is to use an inherently ozone-resistant, saturated backbone polymer in blends with a diene rubber. The ozone-resistant polymer must be used in sufficient concentration (minimum 25 phr) and must also be sufficiently dispersed to form domains that effectively block the continuous propagation of an ozone-initiated crack through the diene rubber phase within the compound. Elastomers such as ethylene-propylene-diene terpolymers, halogenated butyl mbbers, or brominated isobutylene-co-para-methylstyrene elastomers have been proposed in combination with NR and/or butadiene rubber. 

FIGURE 20.7 Phase images of ethylene-propylene-diene terpolymer (EPDM) samples loaded with oil (50 wt%). Image in (a) was obtained on the unvulcanized sample and images in (b,c,d) on samples cross-linked with different amounts of sulfur curative 0.5, 1.0, 1.5 phr, respectively. 

FIGURE 20.12 (a) Top part shows variations of elastic modulus profile measured in different locations of the polypropylene (PP)-ethylene-propylene-diene terpolymer (EPDM) blend. The locations are shown by white dots in the blend phase image placed at the bottom. Vertical white dashed lines show the components borders and the elastic modulus value for this location. Vertical black dotted lines indicate the locations where elastic modulus E gradually changes between PP (E ) and EPDM (E )- These values are indicated with black arrows on the E axis, (b) LvP curves for PP-matrix, EPDM-domains, and one of interface locations. The approach curves are seen as solid black lines and the retract curves as gray lines. 

Medintseva, T.I., Dreval, V.E., Erina, N.A., and Prut, E.V., Rheological properties thermoplastic elastomers based on isotactic polypropylene with an ethylene-propylene-diene terpolymer, Polym. Sci. A, 45, 2032, 2003. 

An oil-based drilling mud can be viscosified with maleated ethylene-propylene elastomers [919]. The elastomers are ethylene-propylene copolymers or ethylene-propylene-diene terpolymers. The maleated elastomers are far more effective oil mud viscosifiers than the organophilic clays used. On the other hand, specific organophilic clays can provide a drilling fluid composition less sensitive to high temperatures [491]. 

Structural Factors and Tensile Properties of Ethylene-Propylene—Diene Terpolymers Prepared with Various Catalyst Systems... 

Ethylene-propylene-diene terpolymers (EPDM), with their inherent complexity in structural parameters, owe their tensile properties to specific structures dictated by polymerization conditions, among which the controlling factor is the catalyst used in preparing the polymers. However, no detailed studies on correlation between tensile properties and EPDM structures have been published (l,2). An unusual vulcanization behavior of EPDMs prepared with vanadium carboxylates (typified by Vr g, carboxylate of mixed acids of Ccj-Cq) has been recently reported Q). This EPDM attains target tensile properties in 18 and 12 minutes at vulcanization temperatures of 150 and l60°C respectively, while for EPDMs prepared with V0Cl -Et3Al2Cl or V(acac) -Et2AlCl, about 50 and 0 minutes are usually required at the respective vulcanization temperatures, all with dieyclopentadiene (DCPD) as the third monomer and with the same vulcanization recipe. This observation prompted us to inquire into the inherent structural factors... 

Thioureas mainly find use for the vulcanisation of CR, epichlorohydrin (ECO) and some ethylene propylene diene terpolymer (EPDM) compounds. They show high crosslinking activity, with usually adequate compound flow time before onset of the crosslinking. In EPDMs, the thioureas are used as activators for low activity third monomer types and, in the presence of calcium oxide desiccants, in free state vulcanisation of extrudates, etc. The use of thioureas can overcome the retardation caused by the desiccant. In this case some care must be taken otherwise overcompensation may occur. Thioureas are not used in food product applications and are a known health hazard, particularly for pregnant women. 

Plant 000027 produces polyisoprene crumb rubber [4.5 x 10" kkg/year (1.0 x 10 lb/ year)] polybutadiene crumb rubber, and ethylene-propylene-diene-terpolymer rubber [EPDM ... 

Polymer International 51,No.7, July 2002, p.601-6 PHYSICAL STUDIES OF FOAMED REINFORCED RUBBER COMPOSITES. PART I. MECHANICAL PROPERTIES OF FOAMED ETHYLENE-PROPYLENE-DIENE TERPOLYMER AND NITRILE-BUTADIENE RUBBER COMPOSITES... 

By rapid expansion of supercritical propane solution (RESS), and isobaric crystallisation (ICSS), isotactic polypropylene and ethylene-butylene copolymers were precipitated from the supercritical solution. The RESS process produced microfibres with a trace of microparticles, while the ICSS process produced microcellular products. Improvement in thermal stability was achieved by first synthesising a thermoplastic vulcanisate from polypropylene and ethylene-propylene-diene terpolymer from a supercritical propane solution, followed by RESS. 28 refs. 

MORPHOLOGY AND PHYSICAL PROPERTIES OF CLOSED CELL MICROCELLULAR ETHYLENE-PROPYLENE-DIENE TERPOLYMER(EPDM) RUBBER VULCANISATES - EFFECT OF SILICA FILLER AND BLOWING AGENT Guriy a K C Tripathy D K Indian Institute of Technology... 

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... 

Post and co-workers [49] have used TG-FTIR to study the outgassing of a plasticiser (type and amount) from an ethylene-propylene-diene terpolymer (EPDM) compound. Figure 1.6 shows the thermogravimetric decomposition behaviour of the EPDM compound. The plasticiser emerges in the first mass-loss step, which was identified as adipic acid diisobutylester by on-line infrared analysis. 

ASTM Method D3900-95 (2000) Standard Test Methods for Rubber-Raw Determination of Ethylene Units in EPM (Ethylene-Propylene Copolymers) and EPDM (Ethylene-Propylene-Diene Terpolymers). 

Infrared methods for copolymer composition like SBR, NBR, ethylene-propylene copolymer (EPM), ethylene propylene diene terpolymer (EPDM) are listed in Table 3.3. 

Sulfonation is very useful chemical modification of polymer, as it induces high polarity in the polymer changing its chemical as well as physical properties. Sulfonated polymers are also important precursors for ionomer formation [75]. There are reports of sulfonation of ethylene-propylene diene terpolymer (EPDM) [76, 77], polyarylene-ether-sulfone [78], polyaromatic ether ketone [79], polyether ether ketone (PEEK) [80], styrene-ethylene-butylene-styrene block copolymer, (SEBS) [81]. Poly [bis(3-methyl phenoxy) phosphozene] [82], Sulfonated polymers show a distinct peak at 1176 cm"1 due to stretching vibration of 0=S=0 in the -S03H group. Another peak appears at 881 cm 1 due to stretching vibration of S-OH bond. However, the position of different vibrational bands due to sulfonation depends on the nature of the cations as well as types of solvents [75, 76]. 

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. 

Similar approaches apply to carbon black - polybutadiene mixtures [45,46]. A thorough study of ethylene-propylene diene terpolymer (EPDM) - carbon black has been developed using NMR a clear evidence for adsorbed EPDM is given in addition to the presence of polymeric strands connecting aggregates to one another [47]. 

Solid-state 13C NMR has been used to identify elastomers in binary blends of chloroprene (CR) and NR, CR and CSM, NR and CSM, and SBR and acrylonitrile-butadiene rubber (NBR). The type of NBR can be determined by identifying the sequences of acrylonitrile and butadiene. The tertiary blend of NR/SBR/BR was also studied [49]. High-temperature 13C solid-state NMR identified ethylene-propylene diene terpolymer (EPDM) and fluoro and nitrile rubbers [50]. 

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... 

Figure 12.1 A typical 129Xe NMR spectrum of a polymer at a temperature above the glass transition temperature (T ) (here ethylene-propylene diene terpolymer (EPDM)) in a ca. 1,000,000 Pa Xe atmosphere. The signal of the free gas is used as an internal...

Xe NMR of an Ethylene/Propylene/Diene Terpolymer in Carbon Black Composites... 

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