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Styrene copolymers with carboxyl groups as corrosion inhibitors for zinc pigments in aqueous alkaline media
Author(s) -
Müller B.,
Imblo G.
Publication year - 1996
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(19960103)59:1<57::aid-app9>3.0.co;2-l
Subject(s) - styrene , copolymer , maleic acid , acrylic acid , aqueous solution , polymer chemistry , acrylate , chemistry , zinc , materials science , organic chemistry , polymer
Zinc pigments react in aqueous alkaline media (e.g., water‐borne paints) by the evolution of hydrogen. Low molecular weight styrene‐maleic acid and styrene‐acrylic acid/styrene‐acrylate copolymers can inhibit this corrosion reaction of zinc pigments in a mixture of water and butyl glycol in the ratio 9 : 1 at a pH value of 10 (ammonia). High molecular weight styrene‐maleic acid copolymers are only very poor corrosion inhibitors. This was proved by volumetric measurement of the evolved hydrogen. There seems to be a correlation between the content of carboxyl groups of the low molecular weight styrene‐maleic acid and styrene‐acrylic acid/styrene‐acrylate copolymers and the evolved hydrogen volume in ammoniacal aqueous medium: The lower the acid number of the styrene copolymers, the lower is the evolved hydrogen volume. Low molecular weight styrene copolymers neutralized with dimethylethanolamine inhibit the corrosion reaction much better than with ammonia. © 1996 John Wiley & Sons, Inc.