Convenient method for preparation of hydrophobically modified starch nanocrystals with using fatty acids

Biodegradable nanoparticles of starch were prepared by an acid treatment process. The obtained starch nanoparticles were hydrophobically modified by using octanoyl, nonanoyl and decanoyl chloride in the aqueous media under mild condition. The structure of the resulted polymers characterized with FT-IR spectroscopy and DS-values calculated by elemental analysis experiment. Thermal characteristic of the modified starch nanoparticles was investigated using TGA technique. By introducing fatty acids, onset temperature for modified starch nanoparticles has increased and starch nanoparticles showed greater thermal stability. Also wettability tests showed that the surface characters of starch nanocrystals have changed during modification and modified starch nanocrystals have higher affinity toward organic solvents rather than aqueous media. DSC studies showed that the starch crystalline structure has not changed during reaction.