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Phenol‐paraphenylenediamine (P‐pPDA) benzoxazines exhibit excellent barrier properties, adequate to protect aluminum alloys from corrosion, and constitute interesting candidates to replace chromate‐containing coatings in the aeronautical industry. For the successful application of P‐pPDA coatings, it is necessary to decrease the curing temperature to avoid the delamination of the coating while preserving the mechanical properties of the alloy, as well as the barrier properties of the coating. However, decreasing the curing temperature leads to less polymerized films, the extent of which requires a quantitative assessment. While the conversion rate of the polymerization reaction is commonly evaluated for bulk samples using differential scanning calorimetry (DSC), a tool for its evaluation in thin films is missing. Therefore, a new approach was developed for that matter using time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). The relation between the SIMS data integrated from inside thin films and the DSC results obtained on bulk samples with the same curing cycle allowed to calibrate the SIMS data. With this preliminary calibration of the technique, the polymerization of PpPDA coatings can be locally determined, at the surface and along the depth of the coating, using dual‐beam depth profiling with large argon cluster beam sputtering.

Oxygen rich organic coatings are synthesized in a dielectric barrier discharge at atmospheric pressure. The critical effect of the precursor structure on the final chemical and physical properties of the synthesized coatings and the plasma characteristics are reported. A correlation is proposed between the electrical, optical emission spectroscopy and atmospheric mass spectrometry (MS) measurements of the plasma phase with the chemical properties of the synthesized films. It is shown that the addition of a precursor in an argon plasma leads to a stabilization of the discharge, critically dependent on the precursor structure itself. Different polymerization pathways are evidenced for the saturated and unsaturated precursors by the monitoring of some specific fragments by MS. The polymerized coatings are also characterized with X-Ray Photoelectron Spectroscopy, Infrared Spectroscopy and Atomic Force Microscopy. The presented results not only evidence a stronger preservation of the precursor structure with double bonds in the plasma phase but also reveal the essential role of the distance separating the unsaturation and a function of interest., SCOPUS: ar.j, DecretOANoAutActif, info:eu-repo/semantics/published

In secondary ion mass spectrometry, hybrid materials such as organic matrices loaded with inorganic nanoparticles (NPs) are notoriously difficult to depth profile with any known ion beam, including large Ar clusters, although they display excellent performance with pure organic materials and polymers. To improve their understanding of the detrimental effects of the hybrid material nature on depth profiling, a precise evaluation of the sputtering and roughness induced upon Cs ion and Ar cluster beam bombardment of a series of composite samples was performed. For this purpose, the authors focused on the sputtering of a selection of extruded, hot-pressed polymer-matrix nanocomposite films by large Ar clusters (20keV Ar1000þ–20eV/at and 10keV Ar3000þ–3.3eV/at) and low energy (500eV) Csþ ions. The selected sample coatings were pure polycarbonate (PC; reference), PC with 5wt. % graphene nanoplatelets, PC with 5wt. % Fe3O4 magnetic nanoparticles (MNPs), and PC with 10wt. % graphene oxide decorated with similar MNPs. The original surfaces and crater bottoms obtained after a fixed ion dose were carefully analyzed by stylus profilometry and atomic force microscopy in order to extract crater depth, sputtering yield, and roughness values. The main observation is that the crater roughness strongly increases in all cases when NPs are mixed with the polymer. However, there are specific behaviors depending on the NP inclusion types and the chosen primary beams. The observed effects are tentatively explained on the basis of fundamental studies of atom and cluster-induced sputtering.

In this paper, laboratory synthesized Phenol-paraPhenyleneDiAmine (P-pPDA) benzoxazine containing different amounts of B-trimesityl-N-triphenylborazine was applied by spin coating on aluminum and thermally cured. The addition of the borazine derivative (borazine 1) does not appear to modify the curing characteristics of the PpPDA matrix itself as shown by FTIR, DSC and DEA analyses; however, some interactions - chemical and/or physical (co-crystallization) – between P-pPDA and borazine 1 cannot be excluded. The microstructure of the composites is characterized by a two phase system consisting of a dispersion of nanosized (10–20 nm) clusters for the lowest borazine 1 concentration (0.5 wt%), evolving towards bigger (100–200 nm), agglomerated clusters for higher borazine 1 concentrations (3 wt%) and finally, continuous, dendritic structures within the P-pPDA matrix for the highest borazine 1 concentration (10 wt%). The benzoxazine composite coating containing 0.5 wt % trimesitylborazine derivative showed a largely increased and durable ability to protect the aluminum substrate. It is shown that a highly capacitive behavior and durable barrier properties can be obtained for P-pPDA coatings containing such a low amount of borazine derivative homogeneously dispersed in the benzoxazine matrix. For concentrations of 3 wt%, as agglomeration took place and dendrites appeared for the highest concentration of borazine derivative (10 wt%), the corrosion resistance decreased with time.