Effect of different compatibilizers on the mechanical and thermal properties of starch/polypropylene blends

Abstract

Starch was treated with three kinds of compatibilizers (coupling agents or modifying agents), KH-550, KH-570, and glycerin monostearate. Blends of polypropylene (PP) and treated starch were prepared by a twin-screw extruder. The effects of the starch before and after treatments and the kinds and contents of the compatibilizers on the mechanical and thermal properties of the PP/ starch blends were investigated in this study. We found that the mechanical properties (tensile strength, impact strength, and elongation at break) of the blends were obviously improved with increasing content of different kinds of compatibilizers. Meanwhile, the most significant improvement in the mechanical properties was obtained in the samples containing just a 1 wt % loading of compatibilizers, and KH-570 had the best improved effects among the different kinds of compatibilizers. The results of thermogravimetric analysis demonstrate that to some extent, the thermal stability of the PP/starch blends was improved after the addition of compatibilizers. Scanning electron microscopy showed that the dispersion of starch in the PP matrix and adhesion between the starch and PP matrix were obviously improved after the addition of compatibilizers. KH-570 not only had the best improved effects among the coupling agents but also still acted as a similar plasticizer.

Gelatinized and nongelatinized starch/pp blends: effect of starch source and carboxylic and incorporation

“…Furthermore, coalescence of gelatinized starch granules and poor dispersion of both phases were observed, probably it was due to the polymer's immiscibility. This incompatibility is associated to the chemical difference of components and was also reported by [17,47,48]. Although we expected a complete gelatinization of starch, SEM images of acid-blends (Fig.…”

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Structure and properties of a compatible starch‐PCL composite using p‐phthaloyl chloride‐based prepolymer

“…This result was consistent with the results of the SEM and the water absorption experiment. The second stage of degradation which was attributed to the thermal decomposition of starch, occurred at around 280 °C . In the range of 320 to 400 °C which was ascribed to the higher decomposition temperature of the PCP compatibilizer, the residue of MS50P50 was higher than that of S50P50.…”

Studies on intumescent flame retardant polypropylene composites based on biodegradable wheat straw

“…Among many researches combining natural biodegradable additives are lignin, starch, and so on into PP polymer to form composites. Those composites are not completely biodegradable but are partly environment‐friendly . Meanwhile, natural biodegradable additives are potential reinforcements for polymer composites for their low density and high specific modulus and strength.…”

“…Those composites are not completely biodegradable but are partly environment-friendly. [3][4][5][6] Meanwhile, natural biodegradable additives are potential reinforcements for polymer composites for their low density and high specific modulus and strength.…”