Aging analysis of polymer coatings for corrosion protection

Duration: 12 months (possible renewal for another 6 months)
Beginning: ~ November-December 2021

Metallic structures are subjected to aggressive environments that degrade their integrity and generate high maintenance costs.

Polymer coatings (paints) are used to ensure the structure durability. Their protective properties are often evaluated by comparing systems in their initial state, i.e., after application of the coating, but rarely after aging. Barrier effect, adhesion or even action of corrosion inhibitors, which are responsible of the protective effect, can however be greatly altered by environmental conditions in service (humidity, oxygen, ultraviolet radiation, etc.). The key parameters for long-term protection are not yet satisfactorily understood1. The objective of this work is to establish relationships between the state of degradation of a coating and its protective performance.

Polymer coatings on steel (or galvanized steel) will first be characterized in the initial state to define their structure (molecular mobility), their adhesion and their level of protection against corrosion. Molecular mobility analysis techniques (calorimetric analysis, dielectric and mechanical spectroscopies) will be used, in addition to electrochemical impedance spectroscopy2,3. These coatings will then be subjected to accelerated or real (marine) aging. The comparison of the different aging conditions should lead to the identification of changes in structures / properties and to the definition of aging acceleration laws.

We are looking for a highly motivated and autonomous candidate, with training and experience in materials science (Doctorate) and more particularly in the physico-chemistry of polymers. Skills in polymer molecular mobility analysis techniques and in impedance measurements on paint systems will be an advantage. A good level in French and / or English (written and oral) is required.

This work will be carried out within the Inter-university Center for Research and Engineering of Materials (CIRIMAT) on the campus of the University of Toulouse (INP-ENSIACET and UPS / Physique), under the supervision of Nadine Pébère and Nicolas Caussé. CIRIMAT is a recognized laboratory in the field of materials science, with equipment and technical support for the characterization of materials. This project is part of a collaboration with the Institute of Corrosion in Brest (paint systems, aging, Raman spectroscopy) and RISE in Sweden (analysis of the chemical structure by infrared spectroscopy).

Location: University of Toulouse, France

Contacts for application (CV and cover letter) before September 20th, 2021
Nadine Pébère (mailto:nadine.pebere@ensiacet.fr) & Nicolas Caussé (mailto:nicolas.causse@ensiacet.fr) & Dominique Thierry (mailto:dominique.thierry@institut-corrosion.fr).

[1] S.B. Lyon, R. Bingham, D.J. Mills, Advances in corrosion protection by organic coatings: What we know and what we would like to know, Progress in Organic Coatings, Volume 102 (2017)[2] A. Roggero, N. Caussé, E. Dantras, L. Villareal, A. Santos, N. Pébère, In situ study of the temperature activated kinetics of water sorption in an epoxy varnish, Polymer, Volume 213 (2021)[3] P. Bonin, A. Roggero, N. Caussé, N. Pébère, D. Thierry, N. Le Bozec, Impedance analysis of the barrier effect of coil-coated materials: Water uptake and glass transition variations, Progress in Organic Coatings, Volume 153 (2021)