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

Abstract

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.

Development of Antibacterial Thermoplastic Starch with Natural Oils and Extracts: Structural, Mechanical and Thermal Properties

“…60TPS decomposes in two distinct stages. Under the test conditions, the first stage takes place between 40 and 190 °C and is due to the gradual evaporation of the remaining water and glycerin, which have weaker interactions with starch [ 47 , 48 ]. It is striking that in all TPS sheets containing TT, the first stage of decomposition presents less weight loss than the 60TPS sheets.…”

Improving the behavior of thermoplastic starch with the addition of gum Arabic: Antibacterial, mechanical properties and biodegradability

“…In the TPS this band is centered at 3291 cm −1 , between those of starch and glycerol. The analysis of the shift of this band is used to evaluate the intensity of the hydrogen bonds [ [31] , [32] , [33] , [34] ]. Nevertheless, due to overlapping the analysis of this band is complicated in this particular mixture; a shift to higher wavenumber with increasing GA content can be observed (from 3294 cm −1 in 60TPS-0.5 GA to 3299 cm −1 in 60TPS-5GA), which cannot be attributed exclusively to the intensity of the hydrogen bonds interaction among components since this band appears at higher wavenumbers in GA (3310 cm −1 ).…”

“…It is also related to the evaporation or decomposition of glycerin and water associated with starch as a consequence of the gelatinization process. Similarly, Liu et al [ 33 ] described four different processes in the thermal decomposition of TPS including sisal fiber. The carbonaceous residue obtained is 9.1 % at 600 °C.…”

Renewable thermoplastic starch/sugar alcohol blends and their oxygen barrier application

“…Oxygen transmission rates (OTR) for starch‐derived materials have been intensively studied for the last several decades 12–39 . The OTR tested at ~25°C/~50% relative humidity (RH) for wheat and potato starch films having ~100 μm thickness were reported as ~16.7 and ~76.8 cm 3 /m 2 ∙day∙atm, 14–16 respectively.…”