INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Nanocomposites reinforced with starch and cellulose nanocrystals using PEO as buffer polymer
Autor/es:
PEREDA, M; EL KISSI, N.; DUFRESNE, A.
Reunión:
Congreso; 41e Colloque National du Groupe Français des Polymères; 2012
Resumen:
Starch nano-crystals (SNCs) and cellulose nano-whiskers
(CNWs) are mainly used as nano-fillers in polymeric matrices because they are renewable and environmentally
benign, naturally abundant, biodegradable, biocompatible and principally
because they allow the production of nanocomposite materials with improved
mechanical properties. The main problem for the preparation of these
nanocomposites is related to the heterogeneous dispersion of nano-fillers
within the polymer matrix, due to strong interactions between them.
Thus, the objective
of this work was to improve the dispersion/compatibilization of nano-particles
in a LDPE matrix using an adsorbed polymer as buffer, with the final aim to
prepare nanocomposites by melt-extrusion techniques. Polyethylene oxide or PEO was chosen to functionalize
the surface of the nano-crystals, by adsorbing itself onto the surface of the CNWs
or SNCs by means of hydrogen bonding. By studying the influence of nano-crystals
concentration on the rheological properties of PEO/nano-fillers suspensions, it
was possible to observe a minimum in viscosity, and also a shifting
of that value at lower concentrations when reducing the PEO molecular weight
from 5,000,000 to 35,000. This value corresponds with a theoretical saturation
point, at which the maximum amount of PEO has adsorbed onto the CNWs and SNCs.
The influence
of the nature of nanocrystals (cellulose and starch) and the molecular weight
of the PEO (from 35,000 to 5,000,000) on the mechanical properties of the
nanocomposites is also studied.