✍ Scribed by Hideharu Mori; Kunihiko Tashino; Minoru Terano
No coin nor oath required. For personal study only.
The effect of hydrogen on the chain transfer reaction in the initial stage of propene polymerization with MgCl~2~‐supported Ziegler catalyst was studied through H~2~‐D~2~ exchange reaction using the stopped‐flow method. When the exchange reaction was carried out with various catalyst components at room temperature for 5 min, HD was produced only in case of using the catalyst with Al(C~2~H~5~)~3~. In case of the stopped‐flow method (reaction time ca. 0.1 s), the catalyst without pre‐treatment with Al(C~2~H~5~)~3~ showed no activity for the H~2~‐D~2~ exchange reaction (no HD produced), while the catalyst with pre‐treatment had exchange activity. As the chain transfer activity of H~2~ in propene polymerization shows the same tendency, it is evident that chain transfer with H~2~ occurs via atomic hydrogen generated on the pre‐treated catalyst.
📜 SIMILAR VOLUMES
MgCl, supports were prepared by the recrystallization method with variation of agitation speed and MgCl, concentration of the MgC1,-methanol-decane mixture. It was found that the particle size of MgCl, and MgCl,/TiCl, could be controlled by changing the MgCl, concentration in a methanol droplet or b
A well-defined diblock copolymer, polypropene-block-poly(ethene-co-propene), was synthesized by modified stopped-flow polymerization with an MgCl 2 -supported Ziegler catalyst. The copolymer shows a unimodal gel permeation chromatography (GPC) elution curve without any material in the low molecular
## Abstract The PdCl~2~‐induced chain transfer reaction by hydrogen in the initial stage of propene polymerization with a MgCl~2~‐supported Ziegler catalyst was studied by means of the stopped‐flow polymerization technique. A chain transfer reaction was found to occur even in the initial stage of t
## Abstract A fine‐grain catalyst, as a model of catalyst fragmentation in the course of polymerization, was prepared by grinding an original MgCl~2~‐supported Ziegler catalyst. In order to clarify the nature of the active sites generated after catalyst fragmentation, the kinetic parameters for pro