| 摘要 |
<p>There is disclosed a low density polymer having a broad molecular weight distribution, such that its melt flow ratio (MFR) is about 50 to about 250, and a substantially constant melt index-corrected density. The polymer, produced e.g., by blending a first polymer component of high molecular weight with a second polymer component of low molecular weight, with both polymer components having substantially the same melt index-corrected density, produces films having improved strength properties and low hexane extractables, as compared to films made from comparable individual polymer components. There is also disclosed a low density polymer, also having MFR of about 50 to about 250, having substantially no polymer chains having low molecular weight and short chain branches, which is prepared by blending a first polymer component of low density and high molecular weight with a second polymer component of relatively high density and relatively low molecular weight. The melt index-corrected densities of these two polymer components are dissimilar.</p> |
