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The mechanism of chain growth in oxidative polycondensation of phenols
Author(s) -
Ionescu Mihail,
Mihis Ana Bianca
Publication year - 1997
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19971220139
Subject(s) - ether , chemistry , phenols , sigmatropic reaction , condensation polymer , oxidative phosphorylation , claisen rearrangement , redistribution (election) , polymerization , chain (unit) , long chain , mechanism (biology) , polymer chemistry , organic chemistry , polymer , polymer science , biochemistry , physics , philosophy , epistemology , astronomy , politics , political science , law
A new mechanism of chain extension in oxidative polycondensation of phenols has been proposed. Between the two accepted mechanisms: quinol ether redistribution and quinol ether rearrangement, the second mechanism seems to be the most important for the chain growth. The first mechanism, quinol ether redistribution, preserves the system average degree of polymerization and assures a permanent equilibration of the polymeric chains, but has only a minor contribution to the molecular weight increase. The second mechanism, quinol ether rearrangement, proved to be the most important for chain extension and was interpreted as a repeated Claisen rearrangement (a particular case of a sigmatropic rearrangement), characteristic to allyl ethers of phenols. Experimental data proved that the above mentioned mechanisms probably take place simultaneously and the real growth of the molecular weight is a result of the cumulative contributions of both mechanisms.