2 research outputs found
Biocomposites from polyhydroxybutyrate and bio-fillers by solvent casting method
Biocomposites from polyhydroxybutyrate (PHB) and some bio-fillers such
as lignin (L), alpha cellulose (AC) and cellulose nanofibrils (CNFs)
were prepared to investigate the effect of the bio-fillers on the
properties of PHB by a solvent casting method. The thermal properties by
thermogravimetry analysis (TGA-DTG and DTA) and differential scanning
calorimetry (DSC) were determined; morphological characterization by
scanning electron microscopy (SEM) and structural analysis by X-ray
diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) of
the biocomposites were performed. TGA curves showed that the highest
values for T-10\%, T-50\% of the biocomposites were 278.2(degrees)C for
PHB+2\%AC and 291.7(degrees)C for PHB+2\%CNFs; however, the best value
for T-75\% was obtained as 381.5(degrees)C for PHB+2\%L. According to
DTG curves, the best results were found for PHB+0.5\%L and
PHB+0.5\%CNFs. DTA showed an increase in temperature of maximum
degradation with loading of lignin and CNFs. The addition of bio-fillers
increases T-c and T-m for both first cooling/heating and second
cooling/heating. T-c and T-m values for first cooling/healing were found
to be lower as compared with second cooling/healing. Furthermore, the
addition of bio-fillers acts as a nucleating agent in PHB and SEM
pictures showed the porous structure in all biocomposites. SEM images
revealed uniform distribution of the reinforcing particles in the
polymer at low loadings (0.5 wt\%), while higher loadings (2 wt\%) of L
and CNFs contributed to easy aggregation within the PHB matrix. In XRD
studies, PHB in the range 5-55 degrees shows 6 main peaks. XRD patterns
of the PHB biocomposites revealed 3 main peaks at 13.57(degrees),
16.87(degrees) and 22.1 degrees, and the other peaks disappeared in the
patterns. The largest and lowest values of X-c were found for PHB+2\%AC
and PHB+2\%CNFs, respectively