Characterizations of modified cassava starch with long chain fatty acid chlorides obtained from esterification under low reaction temperature and its PLA blending

ABSTRACT

In contrast to typical starch esterification in an aqueous solution, which are carried out at elevated to ambient reaction temperatures, a low reaction temperature was applied in this study to minimize the starch chain hydrolysis. The physical properties of the modified starch, obtained from an esterification of cassava starch with long-chain fatty acid chlorides carried out in aqueous media at 4°C, were characterized using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and contact angle measurements. The modified starches show improvement in thermal stability and hydrophobicity, which can be further optimized by varying the types of acid chlorides and the reaction conditions. The starch products have high potential for use as fillers for biodegradable polymers, especially polylactic acid (PLA), as their tunable hydrophobicity can impose strong effect on controlling of the PLA's hydrolytic degradation rate for specific applications. Results on mechanical properties of the blends between the modified starch and PLA show an improvement in modulus of the polymer.

KEYWORDS:

• biodegradable polymer
• biopolymer
• cassava starch
• esterification
• starch modification
• PLA

Acknowledgments

This research was supported by the Thailand Research Fund (TRF, Grant # RSA5980061), the Thammasat University Research Fund, and the Center of Excellence in Materials and Plasma Technology (CoE M@P Tech), Thammasat University.

Additional information

Funding

The Center of Excellence in Materials and Plasma Technology (CoE M@P Tech), Thammasat University. Thailand Research Fund ID: RSA5980061.