Oil-Based and Bio-Derived Thermoplastic Polymer Blends and Composites 257
Table 8.12Properties of five MAPP with different maleic anhydride content
(MA%), molecular weight (Mw) and melt flow index (MFI).
MAPP MA (%) Mw
MFI
(g/10 min) Providers
(A) Polybond 3150 0.5 46,000 20 Crompton Polybond
(B) Polybond 3200 1 42,000 104 Crompton Polybond
(C) G-3003 1.2 52,000 90 Eastman Chemical
Products
(D) E-43 1.2 9,100 ND Eastman Chemical
Products
(E) Bondyram 0.8 66,000 90 Polyram
Kimet al. 2007 [56]. Reproduced with permission of Elsevier.
Kimet al. [56] analysed different maleic anhydride-grafted polypropylene (MAPP)
and their influence on bio-flour-filled polypropylene composites. In particular, they
studied rice husk flour (RHF) and wood flour (WF) as fillers (30 wt%), and they chose
five different MAPP with different percentages of maleic anhydride (MA) graft, molec-
ular weight (Mw) and melt flow index (MFI) – displayed in Table 8.12. The amount
of coupling agent was the 3 wt% with respect to the total weight of the composite
(bio-flour and polypropylene).
An optimization of maleic anhydride percentages andMwis needed in order to
improve composite properties, as shown in Figures 8.14 and 8.15. Low MA content did
not allow obtaining adequate interaction between bio-flour and polypropylene matrix.
On the other hand, high MA content keeps the coupling agent near the hydrophilic
surface, preventing a good interaction with the hydrophobic matrix. Low MAPPMw
Compatibilizing agent type
Tensile strength (MPa)
Non-treatment
PP-RHF 30 wt.%
PP-WF 30 wt.%
A
20
30
40
50
BCDE
Figure 8.14Tensile 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.
