INVESTIGADORES
MOSIEWICKI mirna Alejandra
congresos y reuniones científicas
Título:
Rheological Behavior of Nano-Cellulose Reinforced Polyurethane
Autor/es:
M. A. MOSIEWICKI; T. RICHARDSON; N. E. MARCOVICH; M. I. ARANGUEN; M. L. AUAD
Lugar:
Rio de Janeiro, Brasil
Reunión:
Conferencia; nternacional Conference on Science and Technology of Composite Materials, COMAT2007; 2007
Resumen:
Shape memory polymers are intelligent
materials able to recover their original shape
after being subjected to large strains. In
general, these materials present low stiffness
and small recovery force that limit some of their
applications.
This disadvantage could be overcome with the
incorporation of rigid nanoparticles.
Specifically, cellulose is an interesting
alternative due to its high modulus, high
strength, low cost, low density and wide
disponibility from biodegradable and renewable
resources.
An important concept in the field of nanocomposites
related with the improvement in
properties (mechanical, electrical etc) is the
percolation, defined as a characteristic
threshold concentration (mcG) of filler at which a
step variation in properties occurs. The
reinforcement of polymers using nano-particles,
even in very low concentrations, can generate
important changes in the viscoelastic properties
of the melts. The presence of direct
mechanical contacts between embedded
particles or fibers can give rise to many nonlinear
rheological features. The study of the
viscoelastic properties at low filler concentration
can be used to investigate the occurrence and
location of the percolation threshold. Thus, in
this work, the rheological behavior of molten
polyurethanes (PU) reinforced with
microcrystalline cellulose whiskers was studied.
The results were analyzed using a simple
percolation model.cG) of filler at which a
step variation in properties occurs. The
reinforcement of polymers using nano-particles,
even in very low concentrations, can generate
important changes in the viscoelastic properties
of the melts. The presence of direct
mechanical contacts between embedded
particles or fibers can give rise to many nonlinear
rheological features. The study of the
viscoelastic properties at low filler concentration
can be used to investigate the occurrence and
location of the percolation threshold. Thus, in
this work, the rheological behavior of molten
polyurethanes (PU) reinforced with
microcrystalline cellulose whiskers was studied.
The results were analyzed using a simple
percolation model.