| 摘要 |
This invention relates to a blend composition comprising: 1) a linear ethylene containing polymer, such as a LLDPE, a HDPE or the like; and at least 1 weight percent of an in-reactor polymer blend comprising: (a) a first ethylene containing polymer having a density of greater than 0.90 g/cm3 and a Mw of more than 20,000 g/mol; and (b) a second ethylene containing polymer having a density of less than 0.90 g/cm3, wherein the polymer blend has a Tm of at least 90° C. (DSC second melt), a density of less than 0.92 g/cm3, and the densities of the first and second polymers differ by at least 1%. Alternately the in-reactor polymer blend comprises: (a) a first ethylene polymer comprising 90 wt % to 100 wt % ethylene and from 0 wt % to less than 10 wt % comonomer, said first ethylene polymer component having density of greater than 0.920 g/cm3, an Mw of 20,000 g/mol or more; and (b) a second ethylene polymer comprising from 70 wt % to 90 wt % ethylene and 30 wt % to 10 wt % comonomer, said second ethylene polymer having a density of 0.910 g/cm3 or less, wherein the in-reactor polymer blend has one or more of the following characteristics: (a) at least 78 wt % ethylene; (b) a Tm of at least 100° C. over a density ranging from 0.84 to 0.92 g/cm3; (c) a elongation at break of 300% or more; (d) a strain hardening ratio M300/M100 of at least 1.2; (e) a ratio of complex viscosity at 0.01 rad/s to the complex viscosity at 100 rad/s of at least 30; and (f) a shear thinning index of less than −0.2.
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