Oil-Based and Bio-Derived Thermoplastic Polymer Blends and Composites 263
Figure 8.18Dimensional stability of
polypropylene (PP), high-impact
polypropylene (HIPP), high-density
polyethylene (HDPE) and low-density
polyethylene (LDPE) with different
percentages of paper sludge. Hamzehet al.
2011 [73]. Reproduced with permission fo
Springer.
Thickness swelling (%)
0
0.5
1
- 5
2
10 20
Paper sludge content (%)
30 40
PP
HIPP
HDPE
LDPE
Figure 8.19Flexural strength of
polypropylene (PP), high-impact
polypropylene (HIPP), high-density
polyethylene (HDPE) and low-density
polyethylene (LDPE) with different
percentages of paper sludge. Hamzehet al.
2011 [73]. Reproduced with permission fo
Springer.
600
500
400
Flexural strength (kgf/cm
2 )
300
200
0 10 20
Paper sludge content (wt %)
30 40
PP
HIPP
HDPE
LDPE
8.4 Conclusion
A rising part of the scientific community has chosen renewable materials as subject
for their studies, trying to analyse the main features about this incredible field. In fact,
during last decades, properties and applications of both natural fibres and bio-derived
polymers are easily available, giving the basics for new projects and attractive challenges.
The main reasons for the great interest in bio-derived materials are the renewability,
recyclability and biodegradability: these are three themes deeply studied in these years,
thanks to the improvement in environmental protection. Moreover, the performance
of natural fibres could be comparable to traditional fibres (such as glass fibres), but
a lot of studies must be done in order to potentially substitute traditional fibres with
natural ones.
