Thermoplastic starch-waxy maize starch nanocrystals nanocomposites.
Waxy maize starch nanocrystals obtained by hydrolysis of native granules were used as a reinforcing agent in a thermoplastic waxy maize starch matrix plasticized with glycerol. Compared to our previous studies on starch nanocrystals reinforced natural rubber (NR) [Macromolecules 2005, 38, 3783; 2005, 38, 9161], the present system presents two particularities: (i) thermoplastic starch is a polar matrix, contrarily to NR, and (ii) the chemical structures of the matrix and the filler are similar. The influence of the glycerol content, filler content, and aging on the reinforcing properties of waxy maize starch nanocrystals (tensile tests, DMA) and crystalline structure (X-ray diffraction) of materials were studied. It was shown that the reinforcing effect of starch nanocrystals can be attributed to strong filler/filler and filler/matrix interactions due to the establishment of hydrogen bonding. The presence of starch nanocrystals leads to a slowing down of the recrystallization of the matrix during aging in humid atmosphere.
Centre de Recherches sur les Macromolécules Végétales, CERMAV, ICMG-CNRS, affiliated with Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France.
Hélène
H
Angellier
Sonia
S
Molina-Boisseau
Patrice
P
Dole
Alain
A
Dufresne
D003460:Crystallization; D005990:Glycerol / Q000737:chemistry; D006860:Hydrogen Bonding; D006868:Hydrolysis; D049329:Nanostructures / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction; D003313:Zea mays / Q000737:chemistry*
D013213:Starch; D005990:Glycerol