TY - JOUR

T1 - Hydrogen effect on the molecular weight distribution of polymers obtained by polymerization of ethylene and α-olefins over supported titanium-magnesium catalysts

AU - Matsko, Mikhail A.

AU - Nikolaeva, Marina I.

AU - Zakharov, Vladimir A.

N1 - Funding Information: The authors are grateful to T.B. Mikenas and S. A. Sergeev for samples of TMC‐PE and TMC‐DBP catalysts, O. K. Akmalova, L. G. Echevskaya and A. D. Ryadno for performing 1‐hexene and propylene polymerization. The studies were performed using the equipment of the Center of Collective Use “National Center of Catalyst Research.” This work was supported by Ministry of Science and Higher Education of the Russian Federation. Publisher Copyright: © 2020 Wiley Periodicals LLC Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2021/4/20

Y1 - 2021/4/20

N2 - Comparative data on the molecular weight distribution of polymers obtained by polymerization of ethylene, propylene and 1-hexene, and copolymerization of ethylene with α-olefins over the titanium-magnesium catalysts (TMC) in the absence and presence of hydrogen are presented. In contrast to the ethylene polymerization, in the cases of propylene and 1-hexene polymerization and copolymerization of ethylene with α-olefins, the hydrogen addition is characterized by noticeable narrowing of the molecular weight distribution (MWD) due to lower contribution of the MWD component with high molecular weight. This result is an evidence of the increased reactivity of TMC active sites producing high molecular weight poly-α-olefins and copolymers of ethylene with α-olefins in the chain transfer reaction with hydrogen. It is suggested that the increased reactivity of these sites in the transfer reaction with hydrogen appears after the 2,1-addition of α-olefin to the growing polymer chain.

AB - Comparative data on the molecular weight distribution of polymers obtained by polymerization of ethylene, propylene and 1-hexene, and copolymerization of ethylene with α-olefins over the titanium-magnesium catalysts (TMC) in the absence and presence of hydrogen are presented. In contrast to the ethylene polymerization, in the cases of propylene and 1-hexene polymerization and copolymerization of ethylene with α-olefins, the hydrogen addition is characterized by noticeable narrowing of the molecular weight distribution (MWD) due to lower contribution of the MWD component with high molecular weight. This result is an evidence of the increased reactivity of TMC active sites producing high molecular weight poly-α-olefins and copolymers of ethylene with α-olefins in the chain transfer reaction with hydrogen. It is suggested that the increased reactivity of these sites in the transfer reaction with hydrogen appears after the 2,1-addition of α-olefin to the growing polymer chain.

KW - catalysts

KW - kinetics

KW - polyolefins

KW - CHAIN TRANSFER-REACTIONS

KW - PROPYLENE POLYMERIZATION

KW - ACTIVE-CENTERS

KW - KINETICS

KW - ZIEGLER-NATTA CATALYSTS

KW - PROPAGATION RATE CONSTANTS

KW - PROPENE POLYMERIZATION

KW - 1-HEXENE POLYMERIZATION

KW - COPOLYMERIZATION

KW - LINEAR-POLYMERS

UR - http://www.scopus.com/inward/record.url?scp=85096662652&partnerID=8YFLogxK

U2 - 10.1002/app.50256

DO - 10.1002/app.50256

M3 - Article

AN - SCOPUS:85096662652

VL - 138

JO - Journal of Applied Polymer Science

JF - Journal of Applied Polymer Science

SN - 0021-8995

IS - 16

M1 - 50256

ER -