Properties and Nano-observation of Natural Rubber with Nanomatrix Structure - Natural Polymers, Biopolymers, Biomaterials, and Their Composites, Blends, and IPNs - page 328

electric Property of Natural rubber
Figure 14 shows TEM images for (a) DPNR- graft -PS-1.5, (b) DPNR- graft -PS-4.5
and (c) DPNR- graft -PS-5.5. The ultra thin sections of the DPNR- graft -PS-1.5, the
DPNR- graft -PS-4.5 and the DPNR- graft -PS-5.5 were stained with OsO 4 , in which
the bright domains represent polystyrene and the dark domains represent natural
rubber. As for the DPNR- graft -PS-1.5, the natural rubber particles of about 1 µm in
average diameter, ranging from 50 nm to 3 µm in volume mean particle diameter,
were well dispersed in polystyrene matrix of about 15 nm in thickness. In contrast,
for the DPNR- graft -PS-4.5 and the DPNR- graft -PS-5.5, the natural rubber particles
of about 1 µm in average diameter were dispersed intouncontinuous matrix of con-
densed polystyrene particles of about 60 nm in diameter that are densely close to each
other in the matrix. On the other hand, Figure 14 (d) shows TEM imagesfor thesul-
fonated DPNR- graft -PS-5.5, which was prepared bysulfonation of the DPNR- graft -
PS-5.5 (32 wt% polystyrene) with 0.8 N chlorosulfonic acid. The ultra thin section of
Figure 14. TEM images for (a) DPNR- graft -PS-1.5, (b) DPNR- graft -PS-4.5 (c) DPNR- graft -PS-5.5 and
(d) DPNR- graft -PS-5.5 sulfonated with 0.8 N chlorosulfonic acid 30 °C for 5 h. The ultra thin sections
of about 100 nm in thickness for (a) DPNR- graft -PS-1.5, (b) DPNR- graft -PS-4.5 (c) DPNR- graft -PS-5.5
were stained with OsO 4 at room temperature for 3 min, in which gloomy domains represent natural
rubber and bright domains represent the PS. On the other hand, the ultra thin section of about 100
nm in thickness for (d) sulfonated DPNR- graft -PS-5.5 was stained with RuO 4 for 1 min, in which
bright domains represent natural rubber and gloomy domains represent the PS.