The behavior of the TG mass loss curves was similar in the composites (Fig. 6). The fiber, even at low content (5%,as shown in Fig. 6b), could improve thermal stability, while the effects of fiber contents (Fig. 6b–d) on mass loss at the onset temperature was not obvious. Mass loss at the onset temperature was 15 and 10% for pure TPS and the composites, respectively. For the composites, the moisture content mainly contributed to mass loss at the onset temperature (Curvelo et al., 2001), while for pure TPS the moisture content and the addition of plasticizer resulted in the mass loss. This difference was due to the good adhesion between TPS and fiber. The fiber component decreased the mass loss of plasticizer, therefore, the thermal stability of TPS materials was improved.