Nichakan Panichkul.. A study of abrasion resistance of in situ silica reinforced natural rubber composites. Master's Degree(Materials Engineering). King Mongkut's University of Technology North Bangkok. Central Library. : King Mongkut's University of Technology North Bangkok, 2023.
A study of abrasion resistance of in situ silica reinforced natural rubber composites
Abstract:
This research aimed to prepare natural rubber (NR) composites filled with in
situ silica to improve abrasion resistance. In situ silica filled in NR matrix was carried
out by sol-gel method with tetraethyl orthosilicate (TEOS), catalyzed by n-octylamine,
and using bis[3-(triethoxysilyl) propyl] tetrasulfide (TESPT) as silane coupling agent
for silica surface treatment. The effect of immersion time in TEOS and reaction time
with catalyst on in situ silica generation were studied. The optimal in situ silica content was achieved at 37 parts per hundred of rubber (phr). The morphology in situ silica in terms of dispersion and particles size of in situ silica was investigated by using scanning electron microscope. The size of silica particles was approximately 200 nm. Agglomerates were significantly reduced after TESPT treatment leading to improved silica dispersion.
In situ silica reinforced NR vulcanizates were prepared and characterized compared to commercial silica. The good compatibility between TESPT-treated silica particles and NR matrix resulted in the improvement of mechanical and physical properties. The performance of in situ silica filled NR composites with TESPT in abrasion resistance properties was really improved, nevertheless, commercial silica filled NR composites
offered more favorable outcome. In this study, as the modulus at low strain of in situ silica makes it suitable for applications requiring high modulus at low strain, like
vibration isolation systems, while commercial silica, even when poorly dispersed,
maintained solid mechanical and abrasion resistance properties due to higher amount of silanol groups on its surface reacting more with TESPT than in situ silica. These materials are in a wide range of rubber applications.