| 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 150Å, and in the range of 55 to 97 weight percent of the sum of homotactic sequences of less than 20Å 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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