|
|
ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Published monthly
|
Mechanism of redox initiating system for grafting of vinyl-chloride onto polyethylene
J. Bartuš and J. Beniska
Lehrstuhl für Chemische Technologie der Kunststoffe und Fasern
der Slowakischen Technischen Hochschule, CS-812 37 Bratislava
Abstract: The grafting of vinyl chloride onto hydroperoxidized powdered polyethylene
has been studied under the conditions of emulsion polymerization in the
presence of copper(II) salt, ammonia, and reducing agent. The course of
conversion curves was different when using dienol (ascorbic acid) and reducing
sugar (glucose) as reducing agents. The decomposition of rert-butyl hydrogen
peroxide was done in model conditions for better understanding of the
mechanism of the action of the system. The hydrogen peroxide decomposition
and thus the polymerization of monomer were found to take place after
reduction of the bivalent copper salt to monovalent by endiol anion formed in
the basic medium. The found high value of the efficient activation energy of the
process and almost zero order with respect to the hydrogen peroxide concentration point to the complexity of the elementary processes in the system. The
proposed mechanism explains the course of polymerization as well as the
formation of grafted vinyl chloride copolymer and homopolymer.
Full paper in Portable Document Format: 404a489.pdf
Chemical Papers 40 (4) 489–497 (1986)
|