Composites of Polycaprolactone with Cellulose Fibers: Morphological and Mechanical Evaluation

Abstract

In the present work, alkaline followed by acid treatment was performed on curau a and jute fibers to remove the amorphous portion and to aid fibrillation. X-ray diffraction revealed that the chemical treatments led to better organization of cellulose microfibrils and consequently an increase in their crystallinity index. Thermogravimetric analysis showed a slight decrease in thermal stability of the chemically treated cellulose fibers, however not to the point of preventing their use as filler in polycaprolactone (PCL) matrixes. SEM micrographs revealed that the chemical treatments reduced the fibers' dimensions. Composites of PCL were prepared in a twin-screw extruder, adding different cellulose fibers (treated curau a and jute fibers, commercial cellulose and amorphized cellulose) at 2, 5 and 10 wt.%, maintaining the processing time constant. The results suggest that increasing the fiber crystallinity leads to increased nucleation effect for PCL and that fiber with low crystallinity (amorphized) hinders crystallization of the matrix. Moreover, shorter fibers promote higher nucleation effect in the PCL matrix. SEM micrographs also revealed the presence of nanofibrillated cellulose dispersed in PCL containing chemically treated curau a and jute fibers. Finally, dynamic-mechanical analysis (DMA) showed an increase in modulus and Tg of the composites containing 5 wt.% fibers.

Natural Fiber-Reinforced Polycaprolactone Green and Hybrid Biocomposites for Various Advanced Applications

“…Aguiar et al (2016) [ 126 ] prepared a cellulose–PCL biocomposites and evaluated their mechanical performance. In their work, alkaline and acid pre-treatment were performed on fibres to remove the amorphous portion and to aid fibrillation.…”

Properties of Jute Fibre Reinforced Polymer Composites – A Review

“…The lowest mechanical properties and highest energy absorption were achieved by basalt sandwiched jute epoxy composites. Aguiar et al (2016) studied the effect of alkali (5% NaOH, 1h) and H2SO4 (10%) treatment on the JF/curaua hybrid fibres reinforced polycaprolactone (PCL) composites. Jute fibre treated with H2SO4 has the highest crystallinity index (CI) of 62.9% than other treated fibers.…”

Chemical Modification on Woven Jute and Nonwoven Wet-Laid Glass Fiber Sheet Reinforced Poly-(<i>ε</i>-Caprolactone) Composites

“…Untreated jute initiated the first degradation step around 250˚C, and the second stage starts from 449˚C, which proceeded to accomplish decomposition around 520˚C. Alkali-treated composite overcomes this tendency and degradation completed in a single step due to the removal of hemicellulose as well as increase, and decrease of PCL reinforced molecular mass comparatively affects the thermal degradation process of the composites [48]. Besides, chemically treated woven jute and glass fiber reinforced PCL composites exhibiting improved thermal stability and enhanced the degradation of the composite over untreated composites.…”