X-ray photoelectron spectroscopic analysis of effect of EB on electronic state of Ti species in TiCl4/MgCl2/EB Ziegler-Natta catalysts

Abstract

X-ray photoelectron spectroscopy (XPS) analysis was performed on TiCl 4 /MgCl 2 /EB (ethyl benzoate) catalysts, TiCl 4 /MgCl 2 internal donor free catalysts and TiCl 4 ·EB complex to elucidate the effect of EB on electronic state of Ti species in TiCl 4 /MgCl 2 / EB catalysts. Combined with FTIR analysis, the way that EB influenced electronic state of Ti species was postulated. XPS results showed that the binding energy of Ti 2p3/2 in TiCl 4 /MgCl 2 /EB catalysts was lower than that in TiCl 4 /MgCl 2 internal donor free catalysts indicating that EB influenced electronic state of Ti atoms by providing electrons to Ti atoms in TiCl 4 / MgCl 2 /EB catalysts.

MgCl2‐supported TiCl4catalysts containing diethyl norbornene‐2,3‐dicarboxylate internal electron donor for 1‐butene polymerization: Effects of internal electron donor configuration

“…In order to better comprehend the role of IED configuration on the catalyst performances, much effort has been devoted to the investigation of interaction between the IED with other components of ZN catalysts . IR spectroscopy provides a very useful way to evaluate the interaction of the Mg and Ti species with an IED by comparing the carbonyl group vibrations (ν CO ) shift in the presence of catalyst, MgCl 2 •IED, and TiCl 4 •IED .…”

“…In order to better comprehend the role of IED configuration on the catalyst performances, much effort has been devoted to the investigation of interaction between the IED with other components of ZN catalysts. [38][39][40][41][42] IR spectroscopy provides a very useful way to evaluate the interaction of the Mg and Ti species with an IED by comparing the carbonyl group vibrations (m C@O ) shift in the presence of catalyst, MgCl 2 •IED, and TiCl 4 •IED. 32,[38][39][40][41][42][43][44][45][46][47] As shown in Table III Cat-trans-NDDE showed the highest M w and PDI values, while Cat-endo-NDDE showed best catalyst activity and isospecificity.…”

“…The m C@O band at 1682 cm21 (shifted from 1729 cm21 of pure trans-NDDE) arises from MgCl 2 •trans-NDDE (1682 cm21 ) and the peak at 1640 cm21 of TiCl 4 •trans-NDDE complex disappears. The peak at 1728 cm 21 are assigned to the m C@O of pure trans-NDDE, indicating that only one C@O group of trans-NDDE coordinated to MgCl 2 and not to TiCl 4 in the catalyst, possibly exhibiting a very similar absorption pattern to monoester compounds 38,39,43. Thus, the PB prepared by Cat-trans-NDDE has the lowest I.I value.The shift of m C@O bands also demonstrates that the interaction mainly occurs between exo-NDDE (or endo-NDDE) and MgCl 2 in the catalyst.…”