External donor modified Mg-Ti based Z-N catalyst system for synthesis of Ultrahigh molecular weight polyethylene

This study reported novel external donors Diethyl 2,2'-(dimethylsilanediyl) diacetate (DSD1), Diethyl 2,2'(phenyl(methyl) silanediyl) diacetate (DSD2) and Diethyl 2,2'- (diisopropylsilanediyl) diacetate (DSD3) and triethyl borate (TEB) employed with magnesium dichloride supported Ti-based monoester (Mg-Ti-ME) and magnesium dichloride supported Ti-based diester (Mg-Ti-DE) catalyst for synthesis of Ultrahigh molecular weight polyethylene (UHMWPE). Furthermore, the catalyst was tested with different concentrations of chainterminating agents to understand the effect on molecular weight. The results showed Mg-Ti catalysts using DSD1, DSD2, and DSD3 and TEB external donors had significantly increased molecular weight in the presence of external donors with decreases in catalyst activity, compared to donor-free catalyst systems. In addition, in the presence of chain terminating agent molecular weight decreases significantly with less effect on catalyst activity. The obtained polymer, thermal properties characterized through differential scanning calorimetry (DSC), morphology through a scanning electron microscope (SEM), particle size of resin through a particle size analyzer and molecular weight through viscosity-average molecular weights method.

Automated summary

This study reported novel external donors and their applications with catalysts in the synthesis of Ultrahigh molecular weight polyethylene (UHMWPE). The results showed that the catalysts with external donors had increased molecular weight with decreased catalyst activity. Moreover, the addition of chain terminating agents significantly decreased molecular weight with minimal effect on catalyst activity.