Thermoplastic Starch with Maltodextrin: Preparation, Morphology, Rheology, and Mechanical Properties

Area of Science:

• Materials Science
• Polymer Science

Background:

• Thermoplastic starches (TPS) are versatile biopolymers with potential in various applications.
• Optimizing TPS processing conditions is crucial for enhancing its applicability and reducing energy consumption.

Purpose of the Study:

• To investigate the effect of maltodextrin (MD) and TiO2 nanoparticles on TPS properties and processing.
• To evaluate MD as a processing aid for thermoplastic starch.

Main Methods:

• Two-step preparation: solution casting (SC) followed by melt mixing (MM).
• Rheology measurements at 120 °C.
• In situ torque and temperature monitoring during melt mixing.
• Morphology, thermomechanical, and local mechanical property characterization.

Main Results:

• Maltodextrin (MD) addition decreased TPS viscosity, acting as a lubricant.
• Lower torque moments and processing temperatures were observed for TPS/MD systems.
• A slight decrease in system homogeneity accompanied the viscosity reduction.
• Processing temperature reduction was moderate (approx. 2-3 °C).

Conclusions:

• Maltodextrin is an effective, low-cost processing aid for thermoplastic starch.
• Milder processing conditions offer advantages for energy savings and incorporating sensitive additives.
• TPS/MD systems show promise for technical and biomedical applications.