Nanocomposites based on plasticized starch and rectorite clay: structure and properties

Area of Science:

• Materials Science
• Polymer Science
• Clay Science

Background:

• Plasticized starch (PS) is a biodegradable polymer with potential applications, but its properties require enhancement.
• Modifying natural clay fillers can improve composite performance.
• Cationic guar gum (CGG) can be used to functionalize clay surfaces.

Purpose of the Study:

• To synthesize and characterize CGG-modified rectorite clay (CREC).
• To prepare and evaluate plasticized starch composites incorporating REC and CREC.
• To investigate the effect of these fillers on the thermal stability and water vapor permeability of the composites.

Main Methods:

• Cationic-exchange reaction to synthesize CREC.
• Casting process to prepare PS/REC and PS/CREC composites.
• Rapid Visco Analyser and scanning electron microscopy for material characterization.

Main Results:

• CGG was successfully attached to REC, forming CREC with 30.1% CGG by weight.
• Both REC and CREC acted as reinforcing fillers in the PS matrix.
• Composites showed improved thermal stability compared to neat PS.
• PS/REC composites exhibited a significant decrease in water vapor permeability (WVP), while PS/CREC showed a slight decrease.

Conclusions:

• CGG modification of REC alters its interaction with the PS matrix.
• REC and CREC effectively reinforce plasticized starch.
• REC is more effective than CREC in reducing the water vapor permeability of plasticized starch composites.