Elastomeric ethylene-octene copolymer

Bensason S, Stepanov EV, Chum S, Hiltner A, Baer E. Deformation of elastomeric ethylene-octene copolymers. Macromolecules 1997 30 2436-2444. 

Premphet, K., Chalearmthitipa, S. (2001), Melt grafting of maleic anhydride onto elastomeric ethylene-octene copolymer by reactive extrusion , Polym Eng Sci, 41 (11), 1978-1986. 

Arzondo, L., N. Pino, J. Carella, J. Pastor, J. Merino, J. Poveda and C. Alonso, Sequential Injection Overmolding of an Elastomeric Ethylene-Octene Copolymer on a Polypropylene Homopolymer Core , Pol, Eng, and Sci., 44 (11), 2110 (2004). 

TEM images showing encapsulated and segregated morphologies, respectively (a) PP/maleated EPR 80/20 blend containing 5 wt% silica in the dispersed EPR phase and (b) PP/ethylene-octene copolymer 80/20 containing 5 wt% silica in the matrix. The elastomeric phase appears darker. Blend system studied in Ref. [24]. (Prom Liu, Y. and Kontopoulou, M., J. Vinyl Addit. Technol, 13,147,2007.)... 

COMPARISON OF BLOCK AND RANDOM ETHYLENE-OCTENE COPOLYMERS BASED ON THE STRUCTURE AND ELASTOMERIC PROPERTIES... 

Instead of block copolymers, the use of pseudo-random linear copolymers of an aliphatic a-olefin and a vinyl aromatic monomer has been reported [20], where the styrene content of the polymer must be higher than 40 wt%. Preferred are styrene and ethylene copolymers. These blends may contain, amongst other things, an elastomeric olefinic impact modifier such as homopolymers and copolymers of a-olefins. Presumably the styrene-ethylene copolymer acts as a polymer emulsifier for the olefinic impact modifier. Using 5 wt% of an ethylene-styrene (30 70) copolymer and 20% of an ethylene-octene impact modifier in sPS, a tensile elongation (ASTM D638) of 25 % was obtained. 

An in-reactor TPO may be defined as a reactor-produced polypropylene copolymer (PP-b-E/P), containing between 22 % and 55 % ethylene-propylene copolymer blocks. Small amounts of other comonomers, such as octene-1 or butene-1, may also be present so as to provide unique functionality. In-reactor propylene block copolymers containing less than 20 % ethylene are fairly hard and are usually classified as impact polypropylenes. Reactor-made polymers containing >50 % ethylene are soft and also have relatively poor elastomeric properties - these are classified as plastomers. 

Thermal degradation of blends based on recycled PP and an elastomeric additive, ethylene/ a-octene copolymer (EOC) or synthetic rubber, in low concentration is usually a one-step process and can be kinetically described by using the autocatal)U ic model [a.3]. Figures 43 and 44 show the dynamic TG results obtained. 

The structure and elastomeric properties of the novel olefinic block copolymers (OBCs) were studied by DSC, WAXS, AFM combined with stress-strain, and strain recovery measurement. Their structure and properties were compared with the conventional statistical ethylene-octene (EO) copolymers. The OBCs showed higher strain recovery than the statistical EO copolymers, which is attributed to their unique crystalline morphology. AFM and WAXS studies revealed the elastic spherulites in OBCs. 

Polyolefin-based thermoplastic elastomers (TPEs) have received considerable attention due to their chemical inertness, low density, and low cost compared with other TPEs. Homogeneous ethylene-octene (EO) copolymers, synthesized via contemporary catalyst technology, with low crystallinity and low density (0.86-0.88g/cm ) exhibit the characteristics of thermoplastic elastomers. The elastomeric properties depend on the fringed micellar crystals which serve as network junctions. However, the low melting point of fringed micellar crystals have limited the application of elastic EO copolymers at higher temperatures. 

E-plastomers, based on ethylene and its copolymers with alpha olefins such as propylene or octene, combine the desirable attributes of processibUity, economy, and resistance to environmental degradation [20]. These properties, in conjunction with excellent elastomeric attributes such as... 

Figure 4. Ethylene-co-1-octene density as a function of 1-octene content for elastomeric copolymers.

Studies of ethylene-vinyl aromatic monomer polymerizations continue to be published. Chung and Lu reported the synthesis of copolymers of ethylene and P-methylstyrene [28] and the same group extended these studies to produce and characterize elastomeric terpolymers which further include propylene and 1-octene as the additional monomers [29,30]. Returning to the subject of alternative molecular architectures for copolymers, Hou et al. [31] has reported the ability of samarium (II) complexes to copolymerize ethylene and styrene into block copolymers. 

Polyolefin copolymers started with LLDPE and ethylene-propylene rubber (EPR). Today, there are polyolefin copolymers of ethylene with butene-1, hexene-1, octene, cyclopentene, and norbornene and copolymers of propylene with butene-1, pentene-1, and octene-1 in addition to ethylene. There are copolymers of butene-1 with pentene-1, 3-methylbutene-l, 4-methylpentene-1, and octene in addition to its copolymers with ethylene and propylene. There are copolymers of 4-methylpentene-1 with pentene-1 and hexene-1 in addition to its copolymers with butene-1 and propylene. The function of the comonomers is to reduce crystallinity, as compared to the homopolymers, resulting in copolymers that are highly elastomeric with very low... 

In the polyolefin-based block copolymers, the elastomeric segment is typically a copolymer of ethylene and 1-octene. It is nonpolar and very stable, as is the polysiloxane elastomer segment in the polyetherimide/polysiloxane block copolymers. 

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