TITLE:
Characterization and Comparison of Rheological Properties of Agro Fiber Filled High-Density Polyethylene Bio-Composites
AUTHORS:
Anselm O. Ogah, Joseph N. Afiukwa, A. A. Nduji
KEYWORDS:
Melt Rheology; Agro Fiber; Bio-Composites; Viscoelasticity; High-Density Polyethylene
JOURNAL NAME:
Open Journal of Polymer Chemistry,
Vol.4 No.1,
February
28,
2014
ABSTRACT: The rheological behavior of composites made with high-density
polyethylene (HDPE) and different agro fiber by-products such as corncob (CCF),
Rice hull (RHF), Flax shives (FSF) and Walnut shell (WSF) flour of 60 - 100 mesh were studied. The experimental results were obtained from
samples containing 65 vol.%
agro fiber and 3 wt.%
lubricant. Particle sizes distribution of the agro fibers was in the range of 0.295 mm to ?0.125 mm. SEM showed evidence of complete matrix/fiber impregnation or
wetting. The melt rheological data in terms of complex viscosity (η*), storage
modulus (G'), loss modulus
(G"), and loss tangent (tanδ) were evaluated and compared for different
samples. Due to higher probability of agglomeration formation in the samples
containing 65 vol.% of
agro fillers, the storage modulus, loss modulus and complex viscosity of these
samples were high. The unique change in all the samples is due to the particle
size distribution of the agro fibers. The storage and loss modulus increased
with increasing shear rates for all the composites, except for Walnut shell
composite which exhibited unusual decrease in storage modulus with increasing
shear rate. Damping factor (tanδ) decreased with increasing shear rate for all
the composites at 65 vol.%
filler load although there were differences among the composites. Maximum
torque tended to increase at the 65 vol.% agro fiber load for all composites. Corncob and Walnut shell
composites gave higher torque and steady state torque values in comparison with
Flax shives and Rice hull composites due to differences in particle sizes
distribution of the agro fibers.