258 Introduction to Renewable Biomaterials
Compatibilizing agent type
Izod impact strength (kJ m
−2
)
Non-treatment A B C D E
6
8
10
12
14
PP-RHF 30 wt %
PP-WF 30 wt %
Figure 8.15Izod impact strength trend of polypropylene-rice husk flour (PP-RHF) neat and with five
different compatibilizing agents. Kimet al. 2007 [56]. Reproduced with permission of Elsevier.
does not allow a good mix with the polypropylene matrix, while a highMwcould
provide interface problems. Therefore, G-3003 was considered as the best-optimized
coupling agent, able to induce the best properties in the composite.
Selke and Wichman, using recycled HDPE from milk bottles, with 30 wt% of Aspen
hardwood and 2 or 5 wt% of MAPP, reported another interesting work [57]. A good effect
of MAPP addition with respect to neat HDPE was evident, and as literature revealed, a
suitable MAPP percentages is needed in order to optimize the properties of the analysed
composite. The evolution of elastic modulus is reported in Figure 8.16.
0
100%HDPE
0.2
0.4
0.6
Tensile modulus (GPa)
0.8
- 2
- 4
- 6
- 8
HDPE/WPC
70/30
0% MAPP
HDPE/WPC
68/30
2% MAPP
HDPE/WPC
65/30
5% MAPP
Figure 8.16Tensile modulus trend of recycled HDPE from milk bottles, with 30 wt% of Aspen
hardwood and 2 or 5 wt% of MAPP. Selke and Wichman 2004 [57]. Reproduced with permission of
Elsevier.