resumo
The preparation and characterization of biocomposite materials with improved properties based on poly(lactic acid) (PLA) and bacterial cellulose, and, for comparative purposes, vegetal cellulose fibers, both in their pristine form or after acetylation, is reported. The composite materials were obtained through the simple and green mechanical compounding of a PLA matrix and bacterial cellulose nanofibrils (or vegetable fibers), and were characterized by TGA, DSC, tensile assays, DMA, SEM and water uptake. The bionanocomposites obtained from PLA and acetylated bacterial cellulose were particularly interesting, given the considerable improvement in thermal and mechanical properties, as evidenced by the significant increase in both elastic and Young moduli, and in the tensile strength (increments of about 100, 40 and 25%, respectively) at very low nanofiller loadings (up to 6%). These nanocomposites also showed low hygroscopicity and considerable transparency, features reported here for the first time.
palavras-chave
MICROFIBRILLATED CELLULOSE; THERMAL-PROPERTIES; POLYLACTIC ACID; COMPOSITES; FIBERS; NANOCOMPOSITES; SUBSTITUTION; BIOPOLYMER; MORPHOLOGY; WHISKERS
categoria
Chemistry; Science & Technology - Other Topics
autores
Tome, LC; Pinto, RJB; Trovatti, E; Freire, CSR; Silvestre, AJD; Neto, CP; Gandini, A
nossos autores
Alessandro Gandini
Investigador
Armando Jorge Domingues Silvestre
Professor Catedrático
Carlos Pascoal Neto
Diretor do Raiz
Carmen Sofia da Rocha Freire Barros
Investigador Coordenador
Liliana C. Tomé
Estudante de doutoramento
Ricardo Pinto
Investigadoragradecimentos
FCT (Fundacao para a Ciencia e Tecnologia) is acknowledged for L. C. T. (Research grant PTDC/QUI/68472/2006) and for E. T. (Postdoctoral research grant SFRH/BPD/63250/2009), and for L. C. T. financial support under the scope of the Convenio FCT-CAPES 2009. The authors thank the FCT for funding within the scope of the