2.4. Characterization of composites
Morphology of the fractured surfaces of the TPS and TPS/luffa fiber composites was examined using a scanning electron microscope (SEM) (Quanta 400, FEI). The samples were immersed in
liquid nitrogen before fracturing. The specimens were coated with
a thin layer of gold.
The thermal decomposition temperatures of TPS and TPS/luffa
fiber composites were obtained using a PerkinElmer
TGA 7. The
thermogravimetric analyzer (TGA) was operated at a heating rate
of 10C/min from 50 to 600C under a nitrogen atmosphere.
The Fourier Transform Infrared Spectrometer BRUKER
EQUINOX 55 was used to determine the chemical structure of TPS and
TPS/luffa fiber composite. The dried samples were mixed with
potassium bromide and pressed into a disk shape. The samples
were scanned at a frequency range of 4000–400 cm
1
with 512
consecutive scans in a 4 cm
1
resolution.