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Bulk functionalization of ethylene–propylene copolymers. II. Influence of the initiator concentration and of the copolymer composition and chain microstructure on the reaction kinetics
Author(s) -
Greco Roberto,
Maglio Giovanni,
Musto Pellegrino,
Scarinzi Gennaro
Publication year - 1989
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1989.070370314
Subject(s) - copolymer , materials science , grafting , polymer chemistry , microstructure , surface modification , chemical engineering , kinetics , catalysis , propylene oxide , intrinsic viscosity , ethylene oxide , chemistry , organic chemistry , polymer , composite material , physics , quantum mechanics , engineering
The effect of the dicumylperoxide (DCPO) concentration on the kinetics of the bulk functionalization of an ethylene‐propylene copolymer (EPR) has been studied. It has been found that, enhancing the DCPO initial concentration in the reaction mixture, results in both increased initial reaction rate and grafting process efficiency. DCPO content also affects degradation, which always accompanies the grafting reaction. At high DCPO content, products with a high degree of grafting and intrinsic viscosity close to that of the parent copolymer can be obtained. Furthermore, the influence of the EPR composition and chain microstructure on the functionalization as well as on the degradation processes has been investigated. By increasing the C 2 content in EPRs prepared by using vanadium‐based conventional catalysts, obtains faster functionalization kinetics and a less pronounced degradation of the products. At fixed experimental conditions, the highest grafting degrees have been obtained by using EPRs prepared by high‐yield titanium catalysts and characterized as a block‐like microstructure. The experimental results have been interpreted on the basis of a proposed reaction mechanism.