ISSN:
0887-624X
Schlagwort(e):
free radical polymerization
;
transfer reaction
;
addition-substitution-fragmentation mechanism
;
end-group functionalisation
;
allylic peroxyketal
;
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
A new chain transfer agent, ethyl 2-[1-(1-n-butoxyethylperoxy) ethyl] propenoate (EBEPEP) was used in the free radical polymerization of methyl methacrylate (MMA), styrene (St), and butyl acrylate (BA) to produce end-functional polymers by a radical addition-substitution-fragmentation mechanism. The chain transfer constants (Ctr) for EBEPEP in the three monomers polymerization at 60°C were determined from measurements of the degrees of polymerization. The Ctr were determined to be 0.086, 0.91, and 0.63 in MMA, St, and BA, respectively. EBEPEP behaves nearly as an “azeotropic” transfer agent for styrene at 60°C. The activation energy, Eatr, for the chain transfer reaction of EBEPEP with PMMA radicals was determined to be 29.5 kJ/mol. Thermal stability of peroxyketal EBEPEP in the polymerization medium was estimated from the DSC measurements of the activation energy, Eath = 133.5 kJ/mol, and the rate constants, kth, of the thermolysis to various temperature. © 1994 John Wiley & Sons, Inc.
Zusätzliches Material:
4 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pola.1994.080321409
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