Elaboration de nanocomposites à base de whiskers de cellulose et de polymère acrylique par polymérisation in situ
Auteur / Autrice : | Aymen Ben Mabrouk |
Direction : | Naceur Belgacem, Sami Boufi |
Type : | Thèse de doctorat |
Discipline(s) : | Mécanique, génie mécanique |
Date : | Soutenance le 25/07/2011 |
Etablissement(s) : | Grenoble en cotutelle avec Université de Sfax (Tunisie) |
Ecole(s) doctorale(s) : | École doctorale Ingénierie - matériaux mécanique énergétique environnement procédés production (Grenoble ; 2008-....) |
Partenaire(s) de recherche : | Laboratoire : Laboratoire de génie des procédés pour la bioraffinerie, les matériaux bio-sourcés et l’impression fonctionnelle (Grenoble ; 1995-....) |
Jury : | Président / Présidente : Ali Kallel |
Examinateurs / Examinatrices : Naceur Belgacem, Albert Magnin | |
Rapporteurs / Rapporteuses : Alessandro Gandini, Mustapha Madjoub |
Mots clés
Mots clés libres
Résumé
A stable aqueous nanocomposite dispersion containing cellulose whiskers and a polymer matrix was prepared via miniemulsion polymerization. We were able to prepare a stable dispersion with a 250 wt % solid content and a cellulose whiskers content ranging from 1 up to 5 wt % based on polymer content. Cellulose nanocrytals suspension was mixed with monomers phase in presence of anionic or cationic surfactant and a stabilizing additive acting as a hydrophobe. After sonication for a short time to obtain a stable emulsion of small droplet polymerisation reaction was trigged by the addition of the initiator. The nanocomposite dispersion was characterized using dynamic light scattering, ζ-potential measurement, transmission electron microscopy (TEM), atomic force microscopy (AFM) and FE-SEM. It was found that the particle size of the prepared suspensions is in the range of 90-600 nm, and the final nanocrystals composite is stable for months.Films obtained by casting followed by water evaporation and particle coalescence were analyzed by differential scanning calorimetry, dynamic mechanical analysis, and tensile testing. The nanocomposite maintained high transparency, and their storage elastic modulus increased tediously with the increasing nanowhiskers content.