Decrease in activity caused by hydrogen in Ziegler-Natta ethene polymerisation was written by Garoff, T.;Johansson, S.;Pesonen, K.;Waldvogel, P.;Lindgren, D.. And the article was included in European Polymer Journal in 2001.Safety of 2-Butyl-2-ethylpropane-1,3-diol The following contents are mentioned in the article:
In this study we prepared seven different Ziegler-Natta catalysts and polymerized them at different hydrogen concentrations in order to investigate their kinetic behavior during polymerization The objective was to see whether the results corresponded to what could be expected on the basis of Kissin’s β-agostic deactivation theory. According to this theory, hydrogen causes the formation of dormant sites due to the formation of β-agostic coordination from the Et groups formed after hydrogen termination. According to this theory, the more hydrogen that is used, the more β-agostic coupling and the smaller percentage of Ti in a polymerizing state. This β-agostic coupling would thus explain the lower activity level seen in polymerization where more hydrogen has been used.The results of this study showed that none of the catalysts showed the kind of behavior that would correspond to what could be predicted on the basis of Kissin’s theory. Deactivation could be detected only when a lower amount of hydrogen was used. When higher amounts of hydrogen were used in polymerization there was a clear delay in activation time of the catalysts. This particularly seemed to be the case for catalysts where Ti was present as Ti(IV). This delay in the activation of the catalyst caused a decrease in activity in addition to the normal decrease in activity due to hydrogen replacing C2” in the polymerization process. The only catalyst showing no delay in activation was a silica-based PE Ziegler-Natta catalyst where the Ti was already in trivalent form. In this case no decrease in activity was observed in addition to the normal decrease in activity caused by hydrogen replacing C2” in the polymerization process. This study involved multiple reactions and reactants, such as 2-Butyl-2-ethylpropane-1,3-diol (cas: 115-84-4Safety of 2-Butyl-2-ethylpropane-1,3-diol).
2-Butyl-2-ethylpropane-1,3-diol (cas: 115-84-4) belongs to alcohols. Alcohols are among the most common organic compounds. They are used as sweeteners and in making perfumes, are valuable intermediates in the synthesis of other compounds, and are among the most abundantly produced organic chemicals in industry. Under carefully controlled conditions, simple alcohols can undergo intermolecular dehydration to give ethers. This reaction is effective only with methanol, ethanol, and other simple primary alcohols.Safety of 2-Butyl-2-ethylpropane-1,3-diol
Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts