Ethylene-1-octene copolymer density

LLDPE materials are now available in a range of densities from around 0.900 g/cm for VLDPE materials to 0.935 g/cm for ethylene-octene copolymers. The bulk of materials are of density approx. 0.920 g/cm using butene in particular as the comonomer. 

Melting point alone cannot uniquely identify an OBC. For example, blends of high and low density polyolefins also exhibit an elevated melting point at equivalent density. Sample 3 in Fig. 17 (small circle) is a 70 30 physical blend of 0.86 and 0.94 g cm-3 ethylene-octene copolymers, and the melting point is similar to the OBCs. Physical blends of polymers of such disparate densities are not phase-continuous, however, and segregate into domains of the high and low density polymers. Figure 18 reveals differences in appearance of pressed plaques of the polymer samples... 

Fig. 18 Several samples of ethylene-octene copolymers having similar comonomer content, crystallinity, and melt index. Sample 3 is a physical blend of high and low density copolymers. Samples 4-6 are OBCs prepared with several different levels of chain shuttling agent. Reproduced by permission from [10]...

Fig. 19 Polarized optical micrographs of several polymers. From top left to lower right, a random ethylene-octene copolymer high density polyethylene samples 3-6...

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. 

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). ... 

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

Attane ultra low density ethylene-octene copolymers. Form No. 305-1605-790X SMG, Dow Plastics, Midland, MI. 

Ling, Q. Sun, J. Zhao, Q. Zhou, Q. Microwave absorbing properties of linear low density polyethylene/ethylene-octene copolymer composites filled with short carbon fiber Mater. Sci. Eng., B 2009, 162, 162-166. 

The evolution of systems containing double bonds, for example ethylene-octene copolymer in low density polyethylene blends, is illustrative for the materials with unsaturation orient the behavior during UV exposure (Fig. 2). The contribution of this copolymer is evident. If the gelation of samples does not occur for the first 100 h of exposure [20], the accumulation of radicals allow a sudden increase at 200 h. Then the degradation affects the gel fraction by the cleavage of inter-molecular bridges. 

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%. 

As a binder material. Exact 5361 from ExxonMobil Chemical was used. It is an ethylene octene copolymer made with metallocene catalysist. The density and melt index measured at standard condition were 0.860 g/cm and 3g/10min, respectively. As a filler material Dechlorane Plus 25 Ifom OxyChem was used. It is a hydrophobic flame retardant and has average particle diameter of 5 p m. The SEM microscopy is shown in Fig. 1. It is seen that the particle size of Dechlorane ranges from 1 to 10 p m. 

Content of Ot-Olefin. An increase in the a-olefin content of a copolymer results in a decrease of both crystallinity and density, accompanied by a significant reduction of the polymer mechanical modulus (stiffness). Eor example, the modulus values of ethylene—1-butene copolymers with a nonuniform compositional distribution decrease as shown in Table 2 (6). A similar dependence exists for ethylene—1-octene copolymers with uniform branching distribution (7), even though all such materials are, in general, much more elastic (see Table 2). An increase in the a-olefin content in the copolymers also results in a decrease of their tensile strength but a small increase in the elongation at break (8). These two dependencies, however, are not as pronounced as that for the resin modulus. 

Figure 4 Plot of degree of crystallinity (XDSC) from DSC against crystallinity (Xp) determined by density measurements. (A), hydrogenated polybutadienes ( ), ethylene 1-butene copolymers ( ), ethylene 1-octene copolymers. Reprinted with permission from Ref. [72]. Copyright 1984 American Chemical Society. 

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