3. Results and discussions
3.1. Thermal properties investigation
Prior to polymer processing and bio-composites development,
the thermal characterization of any raw materials and their bio-composites are considered as a crucial step
since the thermal behavior of polymer is capable to suggest
a processing window in order to prevent the potential
thermal degradation. In this study, the weight loss curves
and its derivatives of materials were investigated. Fig. 2a
shows the weight loss curves of raw materials (PLA, WP)
and their bio-composites as opposed to the temperature.
The five percent weight loss (T5%) of PLA appears at about
304 C whereas wood pulp shows T5% loss at about 208 C.
PLA/WP bio-composite exhibits T5% loss at 274 C which
could be attributed to the fiber–matrix at the interface.
Some researchers (Awal et al., 2010; Baltazar-y-Jimenez
et al., 2008) reported that the thermogravimetric analysis
of cellulosic materials occurs three different phases which
includes the loss of moisture (50–100 C), the
depolymerization of cellulose and hemicelluloses
(230– 350 C) and the degradation of more thermally
stable chemical compounds (440– 560 C). In this study,
similar kind of phenomena was observed in wood pulp.
However, bio-composites did not show the similar results
as seen in wood pulp.