Processing and thermo-mechanical characterization of polymer bionanocomposites reinforced with microfibrillated cellulose and cellulose whiskers

par Gilberto Antônio De Freitas Siqueira

Thèse de doctorat en Matériaux, mécanique, génie civil, et électrochimie

Sous la direction de Alain Dufresne et de Julien Bras.

Soutenue en 2010

à Grenoble, INPG .


  • Résumé

    This work describes the use of some Brazilian natural fibers (Sisal, Luffa Cylindrica and Capim Dourado) as sources of cellulose nanowhiskers and microfibrillated cellulose (MFC) for the preparation of polymeric nanocomposites. It proposes a new way of obtaining cellulose nanoparticles and exploits their intrinsic properties. For this purpose two main routes were investigated, namely (i) use of chemically grafted cellulosic nanoparticles reacted with isocyanates and incorporated in a -polycaprolactone (PCL) matrix, and (ii) direct use of cellulose nanoparticles as reinforcement in a natural rubber (NR) matrix. The thermo-mechanical properties were investigated by DSC and DMA. In both cases it was demonstrated that low amounts of fillers provides high mechanical properties when compared to the neat matrix, PCL or NR. The study of crystallization kinetics of PCL and PCL-nanocomposites provided additional information for cellulosic nanofillers acting as nucleating agents accelerating the crystallization process of nanocomposites. Enzymes were also used to prepare such nanoparticles thus yielding nanofillers with different morphologies. As a result, the final NR-nanocomposites showed different mechanical performances and gain in both Young’s and storage modulus with respect to the neat polymeric matrix.


  • Résumé

    This work describes the use of sorne Brazilian natural fibers (Sisal, Luffa Cylindnca and Capim Dourado) as sources of cellulose nanowhiskers and mierofibrillated cellulose (MFC) for the preparation of polymerie nanocomposites. It proposes a new way of obtaining cellulose nanoparticles and exploits their intrinsic properties. For this purpose tvvo main routes were investigated, namely (i) use of cllernically grafted cellulosic nanoparticles reacted with isocyanates and incorporated in a []-polyeaprolactone (PCl) matrix, and (ii) direct use of cellulose nanoparticles as reinforcement in a natural rubber (NR) matrix, The thermo-mechanical properties were investîgated by DSe and DMA. Ln both cases it was dernonstrated that low amounts of fillers provides high mechanical properties when cornpared ta the neat matrix, PCL or NR.

Consulter en bibliothèque

La version de soutenance existe sous forme papier

Informations

  • Détails : 1 vol. (272 p.)
  • Notes : Publication autorisée par le jury
  • Annexes : Bibliogr. 395 réf.

Où se trouve cette thèse ?

  • Bibliothèque : Service interétablissements de Documentation (Saint-Martin d'Hères, Isère). Bibliothèque universitaire de Sciences.
  • Disponible pour le PEB
  • Cote : TS10/INPG/0019/D
  • Bibliothèque : Service interétablissements de Documentation (Saint-Martin d'Hères, Isère). Bibliothèque universitaire de Sciences.
  • Disponible sous forme de reproduction pour le PEB
  • Cote : TS10/INPG/0019
Voir dans le Sudoc, catalogue collectif des bibliothèques de l'enseignement supérieur et de la recherche.