Key-words : epoxy polymers, adherence, interphases, NiCo alloy
Epoxy resins represent a major family of thermosetting polymer precursors. They are encountered in various strategic industrial sectors, such as ground transportation and aeronautics, building and construction, sports and leisure. They are typically used as adhesives and sealants, coatings (e.g. paints, primers...) and composite matrices. They became commercially available since 1946 and were then extensively studied and used since the 1970s. Epoxy resins are often polymerized with amine hardeners, leading to epoxy networks. Independently of the application, the latter always involve interfaces: for example here in adhesives, between a (metal) substrate and epoxy-amine . Such 2D interfaces in 3D multimaterials can be considered as boundaries between two spatial regions occupied by different components. However, at a microscopic scale, these interfaces should more accurately be considered as extended tri-dimensional domains corresponding to so-called “interphases”, which may exhibit physical and/or chemical property gradients.
The ANR AMETIST project aims at capturing the microscopic structuration of the interphase formed by epoxy, amine and metals or alloys so as to understand and ultimately improve the thermal/mechanical properties (such as adherence) of the final polymerized pieces, via the complementary coupling of multi-scale experiments (including 3 complementary in situ approaches) and molecular simulations at both microscopic and macroscopic scales. The following objectives will be aimed:
1) To elucidate the structure and propose a realistic model of the interphase by coupling different experimental and theoretical approaches and better understand the interactions between the different components of the system (including water as a possible secondary compound) as a function of the nature and (hydr)oxidation of the metal and of the nature of the (poly)amine.
2) To link the macroscopic properties (in particular adherence properties) to the interactions and structuration of the interphase.
3) To scale up knowledge from pure metal surface (covered by their oxide) to industrial metal alloys.
4) To identify the best candidate(s) and approaches which can offer the targeted performance or aimed improvements.
For bonding assembly,SAE objectives is to predict the adherence of the joint. In this ANR, with SAE as partner, the main goal of this thesis is the interphases characterisation in order to link the interphase properties and the measured practical adhesion. For this experimental part, epoxide- amine/metal bonded joints will be chosen as model systems. Taking into account the practical adhesion reviews and articles, the three points flexure test (ISO 14679-1997) will be chosen as it guarantees an interfacial failure and the failure initiation measurement (instead of mixture of initiation and propagation mixture measurement). The interphases characterisation will be substantial. Moreover, except mixing calorymetry and Raman spectroscopy (having a confocal microscope) all the other techniques will be post-mortem (FTIR, DSC, . . . ).Benefits
Term and salary
This PhD position is for 3 years (01/11/2022 to 31/10/2025) and the salary (gross) will be at least 1975 euros per month.Selection process
Please send full CV including research interests to Maëlenn AUFRAY and Christophe DROUET, before september, the 20th. Then, job interviews will be organized by visio-conference.
e-mail: email@example.com , firstname.lastname@example.orgAdditional comments
The CIRIMAT Carnot Institute (https:// www. cirimat.cnrs.fr) was created in 1999: this multidisciplinary unit gathers chemists, physicists, crystallographers, metallurgists and polymerists, therefore leading research projects expanding from the conception of materials to the study of their behaviour in use. Several steps are investigated: elaboration, characterization, modelling, as well as optimization of the properties and durability of the materials, and multi-scale approaches in view of industrial development. The CIRIMAT deals with a variety of research themes (both fundamental and applied), and is strongly oriented towards industrial needs, especially via regional, national and European research programs.Offer Requirements Skills/Qualifications
The candidate must have strong background and skills in polymers, and must be interested in modeling in order to follow the work of the other teams of the project.Contact Information