Starch-based composites reinforced with novel chitin nanoparticles

Contrary to the most recognizable whiskers of slender parallelepiped rods, unique nanoparticles of about 50–100 nm were obtained from chitin after consecutive acid hydrolysis and mechanical ultrasonication treatments. Chitin nanoparticles (CNP) exhibited lower crystallinity when compared to conventional chitin whisker. Glycerol plasticized-potato starch (GPS) was combined with CNP to prepare all-natural nanocomposites by casting and evaporation. The morphology, structural, thermal and mechanical properties of the nanocomposites were evaluated by electron microscopy, X-ray diffraction, dynamic mechanical thermal analysis, and tensile tests. At low loading levels, CNP were uniformly dispersed in the GPS matrix and had good interaction between the filler and matrix, which led to improvements in tensile strength, storage modulus, glass transition temperature, and water vapor barrier properties of the GPS/CNP composites. However, at higher loading (greater than 5 wt.%), aggregation of CNP had a negative effect on these properties.