Civil Engineering Reference
In-Depth Information
50
PP matrix
PP/KE (1 mm) 40wt%
PP/KE (10 mm) 40wt%
37.2
40
37.1
35.9
36.5
33.4
34.8
32.4
31.7
28.4
30
20
10
0
(
a
)
clay 0 wt%
clay 5 wt%
clay 10 wt%
PP matrix
PP/KE (1 mm) 40wt%
PP/KE (10 mm) 40wt%
10
8
7.2
7.0
5.9
6
5.4
4.8
4.6
4
3.3
2.6
2.1
2
0
(
b
)
clay 0 wt%
clay 5 wt%
clay 10 wt%
Figure 7.6
Tensile strength and modulus of PP/KE/nanoclay nanobiocomposites. I. Na. Sim
et al.
attributed to the increased stif ness of nanobiocomposites by the addition of KE, and
good interactions between polymer and KE by good dispersion of nanoclay particles.
However, the tensile strength of biocomposites decreased with KE and nanoclay load-
ings. h is can be explained by the bonding between hydrophobic polymer matrix and
hydrophilic natural i ber, which results in signii cant tension stress [25, 26]. As shown
in Figure 7.6, the tensile strength and modulus of PP/KE (10 mm) nanobiocomposites
of 0, 5, 10 wt% nanoclay loadings showed 6.9, 5.3, 14.1% and 4.2, 29.6, 22.0% higher
values, respectively, than those of PP/KE (1 mm) nanobiocomposites. h is can be
explained by the fact that aspect ratio signii cantly af ects the mechanical properties of
hybrid composites resulting from the ef ective stress transfer from i ber of high aspect
ratio to PP matrix [20].
7.3.5 Flexural Properties
h e property enhancement of composite is usually expected by incorporating a higher
volume fraction of reinforcement resulting from the ei cient stress transfer at the
matrix-i ber interfaces. h e stress transfer from the matrix to the i ber depends on
i ber-matrix and i ber-i ber interactions [27, 28].
Figure 7.7 shows the ef ect of nanoclay on the l exural (a) strength and (b) modulus
of PP nanobiocomposites with dif erent i ber length and nanoclay loadings. As shown
in Figure 7.7 , the l exural strength and modulus of PP nanobiocomposites also show a
similar tendency to the tensile strength and modulus, respectively.
