Biomedical Engineering Reference
In-Depth Information
Figure 6.
Conversion and content of styrene for DPNR-graft-PS.
To estimate the grafting efficiency, free polystyrene, which was a mixture present
in the graft-copolymer, was removed by extraction with acetone/2-butanone 3:1 mix-
ture. The grafting efficiency, ν, was estimated as follows:
Mole of PS linked to DPNR
× 100
ν =
Mole of PS produced by reaction
The estimated value of grafting efficiency of styrene is shown in Figure 7. The
grafting efficiency was significantly dependent upon the feed of styrene and it showed
a maximum at 1.5 mol/kg-rubber feed of styrene, as in the case of conversion of sty-
rene. This may be explained to be due to deactivation and chain transfer of the radi-
cals. At 1.5 mol/kg-rubber feed of styrene, almost all polystyrene, thus produced, was
proved to link up to natural rubber as a grafting polymer.
Figure 7.
Grafting efficiency for DPNR-graft-PS.
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