A method of nucleating a propylene homo- or copolymer, the method comprising contacting the propylene polymer with a semi-crystalline branched or coupled polymeric nucleating agent under nucleation conditions. In one embodiment, the propylene homopolymer is characterized as having
13
C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. In another embodiment, the copolymer is characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene, and as having at least one of the following properties: (i)
13
C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), of the copolymer is at least about 3 wt %, (iii) a skewness index, S
ix
, greater than about −1.20, (iv) a DSC curve with a T
me
that remains essentially the same and a T
max
that decreases as the amount of comonomer, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), in the copolymer is increased, and (v) an X-ray diffraction pattern that reports more gamma-form crystals than a comparable copolymer prepared with a Ziegler-Natta (Z-N) catalyst.
一种成核
丙烯同聚物或共聚物的方法,该方法包括在成核条件下将
丙烯聚合物与半结晶支化或偶联的聚合成核剂接触。在一种实施例中,
丙烯同聚物的特征是具有13C NMR峰,相应于大约14.6和大约15.7 ppm处的区位错误,峰强度大致相等。在另一种实施例中,共聚物的特征是包含至少大约60重量百分比(wt%)的来自
丙烯的单元,并具有以下至少一种属性:(i)13C NMR峰相应于大约14.6和大约15.7 ppm处的区位错误,峰强度大致相等,(ii)当共聚物的共单体含量,即来自
乙烯和/或不饱和共聚单体的单元,至少为约3wt%时,B值大于约1.4,(iii)偏度指数Six小于约-1.20,(iv)
DSC曲线具有保持基本相同的Tmethat和随着共聚物中共单体即来自
乙烯和/或不饱和共聚单体的单元增加而降低的Tmax,以及(v)X射线衍射图案报告比使用Ziegler-Natta(Z-N)催化剂制备的相似共聚物更多的伽马形晶体。