Single site catalyzed LLDPE

ACRONYMS, ALTERNATIVE NAMES mLLDPE, metallocene PE, single site catalyzed LLDPE (SSC), polyolefin plastomers (POP), homogeneous ethylene copolymers... 

Heat-shrinkable film comprised single-site catalyzed Babrowicz et al. (1994) copolymer of ethylene and a 3-8C alpha-olefin, LLDPE with p > 9(X) kg m blended with another polymer of ethylene and a 3-8C alpha-olefin and a second comonomer [e.g., vinyl acetate, alkyl acrylate, CO, butadiene, styrene, acrylic acid, and a metal salt of an acrylic acid], or an alpha-olefin homopol3uner. The films had improved shrinkability, impact resistance, and optical properties as compared to prior art and were used in packaging... 

Composition. A representative schematic of the structural differences between LDPE, LLDPE, and single-site-catalyzed LLDPE is given in Figure 1. 

The first commercially available single-site-catalyzed polyethylenes were very low density resins called plastomers (5,6), which had high levels of comonomer and were very homogeneous. Later, commercial commodity grade mLLDPEs were not quite as homogeneous as the plastomers, hut were still more homogeneous than LLDPE (7-9). Figure 3 shows a TREF plot of an LLDPE at 0.918 g/cm density and an mLLDPE at 0.917 g/cm density, both produced in the gas phase. Also included is a plastomer at 0.900 g/cm density produced in a slurry reactor. 

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