In the present study, natural rubber was chemically
modified in two steps, first by graft copolymerization with
MMA monomer, following which the graft copolymer latex
was further modified by in situ epoxidation using formic
acid and hydrogen peroxide. The chemical structures of
the materials were characterized by attenuated total
reflection – Fourier transforms infrared (ATR-FTIR) and
proton NMR spectroscopic techniques. The thermal properties
were analyzed by thermogravimetric analysis
(TGA) and differential scanning calorimetry (DSC). Further,
their polarity or hydrophilicity were investigated by means
of contact angle and swelling measurements. The rubber
plasticity of the materials was also tested.
This novel modified NR with both grafted PMMA and
epoxide groups will be very useful as a compatibilizer for
NR filled with polar fillers such as silica and nanoclay as
well as for rubber blended with polar polymers. In addition,
the cooperative effect of the polar groups may result
in an NR-based material with some special characteristics
such as hydrophilicity and enhanced oil resistance and
thermal stability.