Thermal degradation behavior and structures of thermoplastic cassava starch/sisal fiber composites

The thermoplastic cassava starch (TPS)/sisal fiber (SF) composites were prepared by melt blending. The effects of SF content and its surface treated by sodium hydroxide (NaOH) and silane coupling agent (KH550) on the thermal degradation behavior and structures of TPS were investigated by thermogravimetric‐mass spectrometry (TG‐MS), Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD) and nuclear magnetic resonance (NMR). The thermal decomposition temperatures of TPS/SF composites increase with the SF content. The thermal decomposition products of TPS/SF composites are mainly methane, H2O, acetylene, formaldehyde, methanol and CO2. The thermal stability of composites containing SF treated by NaOH is better than that of KH550. TPS/SF composites show A + V types crystal, and the sample containing SF treated by NaOH has the highest V type crystal. The experimental results reveal that the content and the surface of SF play an important role in the thermal stability and structures changes of TPS/SF composites. TPS/SF composite was prepared through melting mixing method. The thermal behavior was related with the structure of TPS/SF composite.