The present work involved a thorough study on
silane-modified silica filler with special focus on its
chemical interaction with polydimethylsiloxanes (PDMS)
and the structural model of the modified filler. The samples
prepared by addition of modified silica were characterized
by Fourier transform infrared spectroscopy (FTIR), specific
surface test, scanning electron microscopy (SEM) and
fluorescent microscope. FTIR results confirmed the successful
silica surface modification with silane coupling
agent. The sample containing 80 phr (parts per hundreds of
rubber) modified filler with weak ratio of Si–OH/Si–C
group absorbance areas (A1/A0) showed weak formation of
filler agglomerates while a stronger interfacial interaction
could take place between the modified silica and PDMS.
Specific surface results showed that the dispersion of silica
can be improved when the amount of silane modifier to
silica reached 2.0 wt%. SEM and fluorescent microscope
showed that the filler aggregation was observed in cases of
higher silica loading. As expected, when the silica with
surface treatment was compared with those without surface
modification, the filler particles were found to be fairly
well dispersed in PDMS matrix.