A typical 1H NMR spectrum of the modified graft
copolymers is shown in Fig. 3 in comparison with that of
virgin NR, NR-g-PMMA and ENR-30. The absorption bands
at the chemical shifts of 2.7, 3.6 and 5.1 ppm, which indicate
the signals of the methine proton of the epoxidized
unit, the AOCH3 proton of the PMMA and the @CH proton
of the polyisoprene, respectively, can be clearly observed.
These peaks confirm the occurrence of the epoxide group
and grafted PMMA on the NR structure. With increasing
epoxide contents, the peak intensity at 2.7 ppm was clearly
increased, as shown in Fig. 4. The characterization data
from both FT-IR and 1H NMR techniques agree well, and
the modified graft copolymers with various epoxide contents
were successfully prepared in the latex state.