Theoretical investigation of the stereochemistry of the polymerization of. cap alpha. -olefins and dienes with the participation of Ziegler-Natta catalysts

Journal Article · Mon Sep 01 04:00:00 EDT 1986 · Theor. Exp. Chem. (Engl. Transl.); (United States)

OSTI ID:7170156

Minsker, K S; Karpasas, M M

The processes involved in the formation of the active polymerization sites in heterogeneous Ziegler-Natta catalysts have been investigated with consideration of the real structure of the components by the atom-atom potential method, the Monte-Carlo method, a modified diatomics-in-molecules method, and the CNDO/2 method with the aid of the available experimental facts. It has been shown that three types of bimetallic active sites (AS), which differ with respect to the spatial configuration of the coordination sphere, viz., AS-1, AS-2, and AS-3, form, depending on the electronic structure of the homogeneous component R /SUB n/ M, the ionic radius of M (M is a metal from groups I-III), and the unit-cell parameters of the heterogeneous component MeX /SUB m/ (Me is a transition metal from groups IV-VIII). Only the AS-1 sites are stereospecific in the polymerization of ..cap alpha..-olefins and 1,3-dienes (isotactic polyolefins and 1,4-trans-polydienes form); the AS-2 sites are nonstereospecific in the polymerization of ..cap alpha..-olefins, but they form stereoregular 1,4-cis-polydienes; the AS-3 sites are nonstereospecific in the polymerization of both ..cap alpha..-olefins and 1,3-dienes. The phenomenon of stereoregularization in the polymerization of ..cap alpha..-olefins and 1,3-dienes is determined by the steric and electrostatic factors.

• Research Organization: Bashkir Univ., Ufa
• OSTI ID: 7170156
• Journal Information: Theor. Exp. Chem. (Engl. Transl.); (United States), Journal Name: Theor. Exp. Chem. (Engl. Transl.); (United States) Vol. 22:2; ISSN TEXCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKENES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL BONDS
CHEMICAL PROPERTIES
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CHROMIUM CHLORIDES
CHROMIUM COMPOUNDS
COBALT CHLORIDES
COBALT COMPOUNDS
DIENES
ELECTRONIC STRUCTURE
ELECTROSTATICS
HALIDES
HALOGEN COMPOUNDS
HETEROGENEOUS CATALYSIS
HYDROCARBONS
IRON CHLORIDES
IRON COMPOUNDS
MONTE CARLO METHOD
NICKEL CHLORIDES
NICKEL COMPOUNDS
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PHYSICAL PROPERTIES
POLYENES
POLYMERIZATION
STEREOCHEMISTRY
TITANIUM CHLORIDES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
VANADIUM CHLORIDES
VANADIUM COMPOUNDS
ZIEGLER CATALYST