| 摘要 |
A propylene polymeric composition with elastic character that is soluble in at least one nonpolar organic solvent selected from the group consisting of toluene, xylene, heptane, and hexane, comprises greater than 3 weight percent and up to 45 weight percent homotactic sequences each having only r or m diads, all of which homotactic sequences have a helical length in the range of 20 to 150 Å, and in the range of 55 to 97 weight percent of the sum of homotactic sequences of less than 20 Å in helical length, each homotactic sequence having only r or m diads and having fewer than 10 repeat units with mmmm pentads being present in the range of 0 to 35 weight percent of the total composition, and heterotactic sequences having r and m diads of unequal number, the polymer having a molecular weight (Mw) of at least 70,000.
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