Jt. Xu et al., TEMPERATURE RISING ELUTION FRACTIONATION OF POLYPROPYLENES PRODUCED BY HETEROGENEOUS ZIEGLER-NATTA CATALYSTS CONTAINING DIFFERENT INTERNAL DONORS, Polymer Journal, 29(9), 1997, pp. 713-717
Ethyl benzoate (EB), bis(2-ethyl hexyl) sebacate (BEHS), di-n-butyl ph
thalate (DNBP), and bis(2-ethyl hexyl) phthalate (BEHP) were employed
as internal electron donors of heterogeneous Ziegler-Natta catalysts a
nd the obtained polypropylene (PP) samples were fractionated by temper
ature rising elution fractionation (TREF). The influence of different
internal donors on the tacticity distributions of PPs was compared. PP
s have narrower tacticity distributions with aromatic esters. Based on
TREF results, different interactions of internal donor, which may dep
end on their structures, were proposed. The effects of internal donors
on microstructure of the fractions, especially the first fractions, w
ere examined.