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Synthesis, characterization, and electropolymerization of Mannich bases: Influence of substituents on protective ability of organic coatings
Author(s) -
Perrin F. X.,
Pagetti J.
Publication year - 2000
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/(sici)1097-4628(20000222)75:8<1054::aid-app10>3.0.co;2-9
Subject(s) - monomer , polymer chemistry , polymer , chemistry , passivation , phenol , mannich reaction , materials science , organic chemistry , layer (electronics) , catalysis
Abstract Aminoalkyl phenol derivatives were prepared and tested for electrooxidation in alkaline hydroalcoholic electrolytes. We estimated the relative insulating character of thin (<0.3 μm) organic coatings on several metal electrodes (Fe, Cu, and Ni), through both voltammetric and potentiostatic runs. Unsaturated allyl and but‐3‐enyl groups confer the most effective passivation phenomenon, while N ‐methyl‐substituted Mannich bases do not provide the good protective properties expected. This result was explained through the relative easiness of the nitrogen oxidation of these monomers, leading to parasite reactions (methoxylation of the growing polymer chains) and additional termination reactions, thereby limiting the molecular weight of the polymer. FTIRAS results showed that products of the anodic oxidative coupling process consist (especially for the nature of monomer) of a poly(oxy‐1,4‐phenylene)‐type structure. Amino and unsaturated substituted groups remain unchanged during electropolymerization, making the resulting coatings attractive to use as reactive primer layers. The thickness of the coatings was found to reach 2–5 μm in free‐water solutions. This behavior, particular to Mannich bases, was explained by the hydrophilic character of the growing polymer chains due to the presence of amino groups. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1054–1067, 2000