L’équipe matériaux polymères s’intéresse à l’élaboration de matériaux polymères, par voie chimique, photochimique ou physique avec pour objectif fondamental de comprendre et contrôler la relation : composition- structure- propriétés des matériaux résultants.
L’activité de l’équipe peut se concentrer sur :
- Préparation et caractérisation de plusieurs classes de polymères : thermoplastiques, poly électrolytes, polymères cristaux liquides, hydrogels;
- Elaboration et caractérisation des hydrogels à base des monomères acryliques : application dans le piégeage/relargage de molécules toxiques et/ou à effet thérapeutique;
- Développement de réseaux polymères par voie photochimique (UV, visible);
- Dispersion de nanoparticules (nano-oxydes, argiles, zéolites, nanotubes de carbone….) dans des matrices polymères : polymères (nano)composites à propriétés améliorées;
- Développement des polymères couches minces à empreinte moléculaire: Capteurs pour la reconnaissance de molécules pesticides.
« Application Bio-Isopréne: Synthèse de polymères acrylique thermoplastique issus de ressources renouvelables » : Projet à impact socio-économique DGRSDT
« Matériaux membranaires élaboration et application » : Projet à impact socio-économique DGRSDT.
Poly(acrylic acid‑co‑styrene)/clay nanocomposites: efficient adsorbent for methylene blue dye pollutant
Zoulikha Djamaa, Djahida Lerari, Abderrezak Mesli, Khaldoun Bachari
In this contribution, polymer/clay (nano)composites, based on poly(acrylic acid) (PAA) and poly(acrylic acid-co-styrene) poly(AA-co-St), were synthesized by free radical polymerization, using 2,2′-azobis(isobutyronitrile) (AIBN), as initiator and organomodified clay (OMMT), as nanofillers. The structural and morphological characteristics of the obtained (nano) composites, PAA/OMMT (1, 3, 5 wt%), poly(AA75-co-St25)/OMMT (3 wt%) and poly(AA25-co-St75)/OMMT (3 wt%), were examined by X-ray diffraction and scanning electron microscopy, indicating the successful intercalation of polymer chains into the clay nanoplatelets. Thermal properties of obtained (nano)composites were evaluated according to thermogravimetric analysis and differential scanning calorimetry. Based on morphological and thermal results, poly(AA25-co-St75)/OMMT (3 wt%) (nano)composite was selected as an efficient adsorbent matrix for methylene blue dye, with about 74% of elimination obtained after only 80 min of swelling, under soft conditions.
Supramolecular Approach for Efficient Processing of Polylactide/ Starch Nanocomposites
Samira Benali, Farid Khelifa, Djahida Lerari, Rosica Mincheva, Youssef Habibi, Driss Lahem,
Marc Debliquy, Philippe Dubois
All-biobased and biodegradable nanocomposites consisting of poly(L-lactide) (PLLA) and starch nanoplatelets (SNPs) were prepared via a new strategy involving supramolecular chemistry, i.e., stereocomplexation and hydrogen-bonding interactions. For this purpose, a poly(D-lactide)-bpoly(glycidyl methacrylate) block copolymer (PDLA-b-PGMA) was first synthesized via the combination of ring-opening polymerization and atom transfer radical polymerization. NMR spectroscopy and size-exclusion chromatography analysis confirmed a complete control over the copolymer synthesis. The SNPs were then mixed up with the copolymer for producing a PDLA-b-PGMA/SNPs masterbatch. The masterbatch was processed by solvent casting for which a particular attention was given to the solvent selection to preserve SNPs morphology as evidenced by transmission electron microscopy. Near-infrared spectroscopy was used to highlight the copolymer−SNPs supramolecular interactions mostly via hydrogen bonding. The prepared masterbatch was melt-blended with virgin PLLA and then thin films of PLLA/PDLA-b-PGMA/SNPs nanocomposites (ca. 600 μm) were melt-processed by compression molding. The resulting nanocomposite films were deeply characterized by thermogravimetric analysis and differential scanning calorimetry. Our findings suggest that supramolecular interactions based on stereocomplexation between the PLLA matrix and the PDLA block of the copolymer had a synergetic effect allowing the preservation of SNPs nanoplatelets and their morphology during melt processing. Quartz crystal microbalance and dynamic mechanical thermal analysis suggested a promising potential of the stereocomplex supramolecular approach in tuning PLLA/SNPs water vapor uptake and mechanical properties together with avoiding PLLA/SNPs degradation during melt processing.
Prediction of equilibrium swelling ratio on synthesized polyacrylamide hydrogel using central composite design modeling
S. Hamri, D. Lerari, M. Sehailia, B. Dali‑Youcef, T. Bouchaour, K. Bachari.
Central composite design was successfully applied to predict the equilibrium swelling ratio (Y) of a crosslinked polyacrylamide (PAM) hydrogel. Samples were prepared by a facile, simple and efficient photochemical method, using Eosin Y/triethanolamine system as a photo-initiator and 1,6-hexanedioldiacrylate as a crosslinker. The mathematical relationship between the equilibrium swelling ratio and both experimental factors, i.e., temperature (X1) and degree of crosslinking (X2), was evaluated by a second-order quadratic model. The individual and interactive effects of these two parameters were described according to response surface modeling approach. This model allows to predefine the values of the equilibrium swelling ratio of the crosslinked PAM based on experimental conditions, i.e., temperature and degree of crosslinking within intervals [21–78 °C] and [0.75–9%], respectively. As a result, facilitating its application in areas such as drug delivery technology where controlling the swelling of a polymer allows further controlling of drug release. All predicted values were in full agreement with our experimental results [R2 99.85% and R2 (adj) of 99.69% for response Y].