As a result of its excellent reinforcing effect [1–4],
capability of reducing the heat build-up [5] and rolling
resistance of rubber [6], silica is widely used as an indis-
pensable rubber reinforcing filler. However, there are a
number of shortcomings, such as nonrenewability, high
density (2.5 g/cm3
), high energy consumption, and envi-
ronment pollution when silica is mixed into rubber.
Therefore, developing environmentally friendly fillers is
of importance to overcome the disadvantages above.
With a chemical structure similar to starch [7–9], natu-
rally occurring cellulose is a newly emerging reinforcing
filler for rubber. Microcrystalline cellulose (MCC) and
nanocrystalline cellulose (NCC) are highlighted by green
chemists for their characteristics such as renewability,