Adhesion properties of polyelectrolyte-chemisorbed zinc phosphate conversion coatings
It has been reported that when mild carbon cold-rolled steels are immersed in the Zn/sub 3/(PO/sub 4/)/sub 2/ . 2H/sub 2/O-H/sub 3/PO/sub 4/-H/sub 2/O solution systems, the surface microfeatures of crystalline zinc phosphate (Zn . Ph) conversion coating deposited on the steel substrate surface were characterized by large rectangular-like crystal arrays of insoluble Zn . Ph hydrate. Deformation failures of layers having low stiffness characteristics appear to be directly related to the development of micropores and fissures which reduce the effectiveness of the corrosion-resistant coatings. Thus, it is necessary to increase the flexural modulus of the layers in order to restrain the physical deformation failures of the crystalline precoats. The brittle characteristics of the Zn . Ph can be modified by the introduction of the polyacrylic acid (PAA) macromolecules into the phosphating solutions. The incorporation of PAA, which is generally expressed as a polyelectrolyte macromolecule, was shown to form a highly dense fine crystal topography, suggesting that the crystal formation results in an improvement in the stiffness and ductility characteristics of the normally brittle Zn . Ph layers. Accordingly, emphasis of the present paper is given to the finding as to how the molecular structures and functional species of polyelectrolytes act to suppress crystal growth of Zn . Ph and improve interfacial bond durability of Zn . Ph-to-polymeric adhesive joints. 2 refs., 5 figs.
- Research Organization:
- Brookhaven National Lab., Upton, NY (USA)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 6668766
- Report Number(s):
- BNL-38959; CONF-870410-14; ON: DE87005262
- Resource Relation:
- Conference: 193. national meeting of the American Chemical Society, Denver, CO, USA, 5 Apr 1987; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Adhesion properties of polyelectrolyte-chemisorbed zinc phosphate conversion coatings
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACRYLIC ACID
FLEXURAL STRENGTH
CARBON STEELS
CORROSION PROTECTION
SURFACE COATING
ZINC PHOSPHATES
CORROSION RESISTANCE
ALLOYS
CARBOXYLIC ACIDS
DEPOSITION
IRON ALLOYS
IRON BASE ALLOYS
MECHANICAL PROPERTIES
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
STEELS
ZINC COMPOUNDS
400201* - Chemical & Physicochemical Properties