摘要:
Polymer blends that exhibit good impact resistance comprise a crystalline polypropylene matrix and a partly crystalline copolymer impact modifier with a molecular weight lower than that of the matrix polymer. The matrix polymer can comprise any crystalline propylene homo- or copolymer. The impact modifying copolymers are characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene and, in certain embodiments, as having at least one, preferably two or more, of the following properties: (i) 13C 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 of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about −1.20, (iv) a DSC curve with a Tme that remains essentially the same and a Tmax that decreases as the amount of comonomer 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.
摘要翻译:表现出良好抗冲击性的聚合物共混物包括分子量低于基体聚合物的结晶聚丙烯基质和部分结晶共聚物抗冲改性剂。 基质聚合物可以包含任何结晶丙烯均聚物或共聚物。 抗冲击改性共聚物的特征在于包含至少约60重量%(wt%)衍生自丙烯的单元,在某些实施方案中,具有至少一个,优选两个或更多个以下性质:(i) 对应于约14.6和约15.7ppm的区域误差的13 C NMR峰值,大约相等强度的峰值,(ii)当共聚物的共聚单体含量在...时,B值大于约1.4 至少约3重量%,(iii)偏度指数大于约-1.20,(iv)具有基本上保持的T曲线的DSC曲线 相同和最大值随着共聚物中共聚单体的量的增加而减小,和(v)报告比用齐格勒制备的可比共聚物更多的γ型晶体的X射线衍射图 -Natta(ZN)催化剂。