1. Laboratorio de Polímeros y Materiales Compuestos, Dep. De Física, FCEN – UBA, Ciudad Universitaria, C1428EGA, Ciudad Autónoma de Buenos Aires, Argentina;2. Universidad Nacional de San Martín (UNSAM), Buenos Aires, Argentina;3. Grenoble Institute of Technology (INPG) The International School of Paper, Print Media and Biomaterials (PAGORA) – BP 65 – F‐38402 Saint Martin d'Hères Cedex, France;4. INTEMA, Univ. Nacional de Mar del Plata, Av. Juan B. Justo 4302 7608FDQ, Mar del Plata, Argentina
Abstract:
Nanocomposites of cassava starch reinforced with waxy starch nanocrystals were prepared. They showed a 380% increase of the rubbery storage modulus (at 50 °C) and a 40% decrease in the water vapor permeability. X‐ray spectra show that the composite was more amorphous than the neat matrix, which was attributed to higher equilibrium water content in the composites. TGA confirmed this result and its thermal derivative suggested the formation of hydrogen bonding between glycerol and the nanocrystals. The reinforcing effect of starch nanocrystals was attributed to strong filler/matrix interactions due to the hydrogen bonding. The decrease of the permeability suggests that the nanocrystals were well dispersed, with few filler/filler interactions.
