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Polycaprolactone (PCL) has been blended with thermoplastic starch (TPS), prepared from regular corn starch and glycerol, in a twin‐screw extruder. The rheological, mechanical, thermal and morphological properties of the blends were examined. Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) studies revealed that PCL/TPS blends are thermodynamically immiscible. However, they form compatible blends as a result of the hydrogen bonding interaction between the ester carbonyl of PCL and the OH groups on starch. Biodegradability of the blends increased with increasing TPS content. Dynamic viscoelastic measurements concluded that blends containing above 60‐wt% TPS had higher storage and loss moduli than those of pure TPS and PCL. In addition, these blends had higher complex viscosities. Polym. Eng. Sci. 44:1429–1438, 2004. © 2004 Society of Plastics Engineers.

In this study, poly(lactic acid) (PLA) was blended with chemically modified thermoplastic starch (CMPS) in a twin-screw extruder. The characteristic properties of PLA/CMPS blends were investigated by observing the morphology, thermal, and mechanical properties, and biodegradability. Differential scanning calorimetry showed that the PLA/CMPS were thermodynamically immiscible. However, scanning electron microscopy and Fourier transform infrared studies revealed that the interfacial adhesion was improved by the PLA-gstarch copolymers that were formed at the interface through a transesterification reaction between PLA and CMPS. The crystallinity of the PLA component in the blend was increased by the addition of the CMPS and was highly affected by the morphology of the blend. The tensile strength and elongation were found to decrease in a linear trend with increasing CMPS content. The biodegradability of the blends increased with increasing CMPS content, while initial time lag decreased. POLYM. ENG. SCI., 51:826-834, 2011. ª 2011 Society of Plastics Engineers Recently, in our work, chemically modified thermoplastic starch (CMPS) was introduced [27-30].This article aims at reporting on the utilization of CMPS to tailor biobased and biodegradable PLA blends for applications requiring a balance between cost and properties. To meet this objective, we prepared CMPS through the reactive extrusion processing of starch in the

The effect of chemically modified thermoplastic starch (CMPS) on the thermal properties and isothermal crystallization kinetics of poly(lactic acid) (PLA) was studied by differential scanning calorimetry (DSC) and compared to that of granular starch and an inorganic nucleating agent, talc. Nucleated PLA showed an additional crystallization of PLA, which affected the melting temperature. The crystallinity and crystallization rate of PLA were considerably enhanced by addition of CMPS, even at 0.1% content, and the amount of the CMPS had little effect on the thermal properties and isothermal crystallization kinetics of PLA. The effect of CMPS as a nucleating agent was comparable to that of granular starch but slightly less than that of talc. However, CMPS can offer a fully biodegradable nucleating agent with no residues remaining for the biobased and biodegradable polymers.

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