Ethylene-octene copolymer elastomers

Influence of nanosilica (Si02) and elastomer concentrations on the mechanical properties of TPOs, comprising of a PP/PP-g-MA matrix and a dispersed ethylene-octene copolymer elastomer, at a 80/20 ratio by weight- Silica content is 5 wt% (a) flexural modulus and (b) impact strength. (Data from Liu, Y. and Kontopoulou, M., Polymer, 47,7731,2006.)... 

Engage polyolefin elastomers (POE), ethylene octene copolymer elastomers, produced by DuPont Dow Elastomers, use Insite catalytic technology. Table 3.2 shows their low density and wide range of phys-ical/mechanical properties (using ASTM test methods). ... 

The new metallocene ethylene elastomer TPOs now used in the automotive industry possess better low-temperature impact properties and better lifetime durability than soft vinyl plastic. Some new proprietary ethylene-octene copolymer elastomers are being used as TPOs as well, and a new introduction of an ethylene-butene copolymer has been made as well. 

The new single-site metallocene technology can be employed to yield new polyolefin materials (polyolefin plastomers (POP) and polyolefin elastomers (POE)) as noted by Schwank in the above noted reference. POP and POE materials are based on ethylene-octene copolymers and should show promise in various future blend combinations. 

The CG catalysts produce highly processable polyolefins with a unique combination of narrow MWD and long chain branches. Ethylene-octene copolymers produced with CG catalysts have useful properties across a range of densities and melting indexes. These novel copolymer families are called polyolefin plastomers (POP) and polyolefin elastomers (POE). POPs possess plastic and elastic properties while POEs containing greater than 20 wt% octene comonomer units have higher elasticity. 

The comparison of TGIC and TREF for a series of ethylene octene copolymers has been reported by Monrabal et al. [123], showing that resolution on TREF is slightly better than TGIC. TGIC, however, does not suffer from co-crystallization effects and covers a broader copolymer range down to the elastomer region, which crystallization techniques cannot reach. 

In ternary nanocomposites, compatibilizers have been mostly used to improve the adhesion at the polymer/filler interface rather than to modify the polymer/elastomer interface. Mishra et al. [80] compounded PP/EPDM/organoclay (75/25/5 wt%) and added PP-g-MA (1 wt% MA) as a compatibilizer with a clay/PP- -MA ratio of 1/3. They characterized the interlayer spacing of the clay platelets by XRD and observed that it increased from 3.4 to 4.3 nm for systems without and with compatibilizer. This was attributed to a better diffusion of the PP-g-MA chains inside the interlayer spacing thanks to their functional groups. Numerous other authors prepared and characterized ternary composites with a compatibilizer. Examples include Lim et al. [81] and Lee et al. [5] on PP/PP- -MA/POE/ organoclay systems, Mehta et al. [23] on PP/PP-g-MA/EPR/organoclay systems, and Liu and Kontopoulou [24,45] on PP/PP-g-MA/ethylene-octene copolymer/silica composites. It should be noted that the compatibilizer itself may affect the properties of the matrix... 

Basuli, U. Chaki, T. K. Naskar, K., Mechanical Properties of Thermoplastic Elastomers Based on Silicone Rubber and an Ethylene-Octene Copolymer by Dynamic Vulcanization. J. Appl. Polym. Sci. 2008,108,1079-1085. 

Six companies currently market metallocene plastomers. Exxon Chemical manufactures and markets ethylene-butene and ethylene-hexene copolymers under the EXACT tradename. Dex-Plastomers, a joint venture of Exxon Chemical and DSM, manufactures ethylene-octene copolymers under the EXACT tradename, which are sold by both partners. Dow Chemical and DuPont Dow Elastomers offer ethylene-octene copolymers. Their tradenames are, respectively, AFFINITY and ENGAGE. Japan Polychem manufactures and markets ethylene-hexene copolymers under the KERNEL tradename. Mitsui Petrochemical manufactures propylene, butene, and octene copolymers sold under the TAFMER tradename, along with nonmetallocene plastomers. 

EO Plastomer ENGAGE 8100 ethylene octene copolymer, 1.0 MI, 0.87 density, from Dupont Dow Elastomers. 

Poly(ethylene-octene) Copolymer/PLA Blends Poly(ethylene-octene) copolymer, a thermoplastic polyolefin elastomer (TPO), was melt blended with PLA at a ratio of 20/ 80 wt% [10]. The difference in polarities of the two polymers led to thermodynamic immiscibility and phase separation of the final blends as determined by the Molau test. Therefore, a copolymer of TPO-gra//-PLA (TPO-PLA synthesized via functionalization of TPO and MA with benzoyl peroxide (BPO), followed by esterification of the MA-functionalized TPO (TPO-MAH) with PLA using 4-dimethylaminopyridine (DMAP) as a catalyst) was introduced to improve the compatibility of the TPO/PLA blends. The use of 5 wt% TPO-... 

Acrylonitrile-butadiene rubber (NBR) - Europrene N3960, acrylonitrile unit content 28 % produced by Lanxess, ethylene-propylene rubber (EPM) Dutral CO 054, propylene unit content 40 % produced by Montedison Ferrara, silicone rubber - Polymer MVQ 0,07 produced by Z. Chem. Silikony Polskie Sp. z o.o., Nowa Sarzyna, ENGAGE Polyolefin Elastomer ethylene-octene copolymer produced by DOW Chem. Comp. USA, polyoctenamer VESTENAMER 8012 -semicrystalline rubber produced by Degussa GmbH Germany. 

Bensason et al. [81] reported the properties of a series of ethylene-octene copolymers made using Dow CGC technology. In addition to LLDPE, these products included plastomers having densities from 0.89 to 0.91 and crystalhnities between 23 and 39 percent and thermoplastic elastomers having densities below 0.89 and crystallinities between 10 and 23%. 

In this study, two kinds of base material were used a prevailingly linear neat PP (PP DM55pharm) and a thermoplastic polyolefin elastomer (Engage 8407), supplied by Borealis and Dow Chemical, respectively. Specific material data can be found on the manufacturers homepages [6, 7]. Engage 8407 is an ethylene-octene copolymer (EOC) with a monomer-ratio of 60% to 40% for ethylene and octene, respectively. It contains untreated talc particles of 1 /an (ave.) in size. Engage 8407, when blended with PP or polyethylene, can improve the overall impact performance and can also act as a melt flow enhancer to aid processing. 

For the production of ethylene/l-octene copolymers, metallocenes in combination with oligomeric methylalumoxanes or other compounds are now used [31, 63]. Half-sandwich transition metal complexes such as [(tetramethyl- / -cyclopentadienyl) (A-/-butylamido)dimethylsilyl]titanium dichloride are applied to synthesize linear low-density copolymers and plastomers, called constrained geometry catalysts [31]. Ethylene and styrene can be copolymerized to products ranging from semicrystalline mbber-like elastomers to highly amorphous rigid materials at room temperature [64]. 

While the range of the new metallocene-based polymers includes such specialty polymers as cyclo-olelin copolymers (COC), syndiotactic polystyrene, ethylene/ styrene copolymers, which are stiU in the developmental stage, commercially, the most prominent candidates are the elhylene/a-olefin copolymers such as ethylene/ butylene or hexene copolymers (Exxon s Exact ) or ethylene/l-octene copolymers (Dow s Engage and Affinity ). Depending on the comonomer content, these copolymers have been classified as plastomers or elastomers. At comonomer levels of >25 %, the copolymers exhibit the characteristics of thermoplastic elastomers such as high softness, toughness, flexibility, and resilience and hence been referred to as polyolefin elastomers (POE). CompositionaUy, these POEs usually contain 65 % ethylene and 35 % octene-1, hexene-1, or butene-1 as comonomers. 

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