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A novel strategy was developed to prepare a self-blowing poly(β-hydroxythioether) foam at room temperature by S-alkylation of 5-membered bis-cyclic carbonate using multifunctional thiol monomers. Two different thiol compounds, trimethylolpropane tris(3-mercaptopropionate) and pentaerythritol tetrakis(3-mercaptopropanoic acid) were used for the decarboxylative s-alkylation reaction. The thiol compounds simultaneously act as crosslinking agents and generate carbon dioxide during the decarboxylative s-alkylation reaction. This enables foam preparation without an external blowing agent. The use of tetrathiol monomer improves thermal stability, provides flexibility to the foams, and induces an increase in the glass transition temperature (Tg) due to a higher degree of cross-linking. The apparent density of the foams decreases with the increase of the tetrathiol ratio. This novel solvent-free approach paves the way to design sustainable foams with modular properties using accessible components and additives, as well as provides an alternative to non-isocyanate polyurethane foams., The CNRST of Morocco acknowledged for funding this work from Projet Prioritaire (PPR1/2015/73)

The consequence of coupling wear (erosion/abrasion) and corrosion is not just simply the sum of wear in the absence of corrosive medium and corrosion in absence of wear. The so-called synergistic effect implies that corrosion is accelerated due to the removal of the passivating layer because of wear. On the other hand, corrosion can accelerate abrasion when the electrochemical dissolution yields a brittle surface layer which can be subsequently removed by abrasion. The synergism between wear and corrosion is complex and the interaction between mechanical and chemical factors governing tribocorrosion is not yet fully understood. This review aims at providing a general and thorough summary of the wear-corrosion interaction focused on stainless steels due to the technological relevance of these materials. It is taken into consideration the influence of the key parameters affecting wear-corrosion, such as the stainless steel type, slurry characteristics (temperature, pH, solid concentration), the erodent properties (particle size and shape), etc. The different models to describe wear-corrosion and the most used apparatus for tribocorrosion testing are also reviewed.

International audience; Three-dimensional hydroxyapatite-chitosan (HA-CS) composites loaded with ciprofloxacin antibiotic (HA-CS-CIP) were formulated using the in situ and the solid-liquid method coupled with the freeze-drying process. The interaction of the HA-CS composite powder and ciprofloxacin antibiotic (CIP) was investigated by batch adsorption essays. The kinetic and the isotherm data were fitted well to the pseudo-second-order and Freundlich models, respectively. The compressive strength of the HA-CS composite was increased by 7-fold and 10-fold when using respectively 15 wt% and 30 wt% of the polymer compared to the HA-CS5 formulation (3.6 +/- 0.7 MPa) made only from HA powder and CS gel (5 wt%). However, this parameter decreased from 36.8 +/- 8.5 MPa down to 20.5 +/- 4.7 MPa when the antibiotic content increased from 0 up to 9 wt%, respectively. The in vitro release results showed a sustained and controlled CIP release for up to 10 days. The release data fitting and modeling indicate that the process follows a Fickian diffusion mechanism. Also, the formulated composite revealed an antibacterial effect against Staphylococcus aureus and Escherichia coli bacteria. The developed

International audience; This work aims to develop an injectable and antibacterial composite cement for bone substitution and prevention/treatment of bone infections. This cement is composed of calcium phosphate, calcium carbonate, bioactive glass, sodium alginate, and ciprofloxacin. The effect of ciprofloxacin on the microstructure, chemical composition, setting properties, cohesion, injectability, and compressive strength was investigated. The in vitro drug release kinetics and the antibacterial activity of ciprofloxacin-loaded composites against staphylococcus aureus and Escherichia coli pathogens were investigated. XRD and FTIR analysis demonstrated that the formulated cements are composed of a nanocrystalline carbonated apatite analogous to the mineral part of the bone. The evaluation of the composite cement’s properties revealed that the incorporation of 3 and 9 wt% of ciprofloxacin affects the microstructural and physicochemical properties of the cement, resulting in a prolonged setting time, and a slight decrease in injectability and compressive strength. The in vitro drug release study revealed sustained release profiles over 18 days. The amounts of ciprofloxacin released per day (0.2 -15.2 mg/L) depend on the cement composition and the amount of ciprofloxacin incorporated. The antibacterial activity of ciprofloxacin-loaded cement composites attested to their effectiveness to inhibit the growth of Staphylococcus aureus and Escherichia coli.

Polyurethane foams (PUFs) are a significant group of polymeric foam materials. Thanks to their outstanding mechanical, chemical, and physical properties, they are implemented successfully in a wide range of applications. Conventionally, PUFs are obtained in polyaddition reactions between polyols, diisoycyanate, and water to get a CO foaming agent. The toxicity of isocyanate has attracted considerable attention from both scientists and industry professionals to explore cleaner synthesis routes for polyurethanes excluding the use of isocyanate. The polyaddition of cyclic carbonates (CCs) and polyfunctional amines in the presence of an external blowing agent or by self-blowing appears to be the most promising route to substitute the conventional PUFs process and to produce isocyanate-free polyurethane foams (NIPUFs). Especially for polyhydroxyurethane foams (PHUFs), the use of a blowing agent is essential to regenerate the gas responsible for the creation of the cells that are the basis of the foam. In this review, we report on the use of different blowing agents, such as Poly(methylhydrogensiloxane) (PHMS) and liquid fluorohydrocarbons for the preparation of NIPUFs. Furthermore, the preparation of NIPUFs using the self-blowing technique to produce gas without external blowing agents is assessed. Finally, various biologically derived NIPUFs are presented, including self-blown NIPUFs and NIPUFs with an external blowing agent., This research is part of grant PID2020-119546RJ-I00 funded by MCIN/AEI/10.13039/501100011033.