CIPRIANO, P. B.; http://lattes.cnpq.br/0618268338472163; CIPRIANO, Pâmela Bento.
Résumé:
Fully natural and biodegradable composites of commercial poly(3-hydroxybutyrate)
(PHB) and fiber of the mesocarp of the fruit of the babacu palm were
prepared with 5, 10, and 20% of vegetable fiber of two different granulometries,
processed in an internal mixer. Matrix, load, and composites were characterized
by melt flow index (MFI), infrared spectroscopy (FTIR), thermogravimetric
analysis (TGA), differential scanning calorimetry (DSC) and optical microscopy
(OM). The matrix (PHB) was found thermally unstable at processing
temperatures. The load level and particle size significantly affected the melting
and crystallization processes of PHB in the composites, in both its
thermodynamic (melting temperature, crystallinity) and kinetic (crystallization
rate) characteristics, suggesting that the mesocarp of babacu acted as a
nucleating agent. Analysis of microphotographs showed that the load was well
dispersed during processing. Particle size distribution was determined and the
effect of loading level and granulometry was found to affect the mean particle
size and breadth of the size distribution. It was found that the mixing process
significantly decreases particle size, which becomes a function of the loading
level.