Sol‐gel process of alkyltriethoxysilane in latex for alkylated silica formation in natural rubber

Abstract

Sol‐gel process of alkyltriethoxysilanes that was dispersed in natural rubber latex was used to generate alkylated silica particles inside the rubber matrix. Three types of alkyltriethoxysilanes were chosen, i.e., vinyltriethoxysilane (VTOS), ethyltriethoxysilane (ETOS), and i‐butyltriethoxysilane (BTOS), as they differed in the type of one substituent group. Together with tetraethoxysilane (TEOS), a typical precursor for silica formation, all silanes were studied for their conversion to silica and subsequent reinforcement capabilities in sulfur‐vulcanized rubber. The in situ generated silicas were fine and well dispersed in the rubber matrix, as analyzed by SEM and TEM. Solid‐state 29Si‐NMR technique was used to confirm the presence of alkyl substituents on the silica particles buried inside the rubber matrix. Tensile and tear properties of the in situ silica‐filled NR vulcanizates were higher than those of the vulcanizate prepared by conventional mixed method. Among the three alkyltriethoxysilanes used, only VTOS, when used as a mixture with TEOS, did not cause a reduction in silica formation. The resulting vinylated silica tended to enhance the tensile modulus and resistant to tear of the rubber vulcanizates. Cure characteristic and swelling behavior in toluene of the silica‐containing vulcanizates were also investigated. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

Effect of silane integrated sol–gel derived in situ silica on the properties of nitrile rubber

“…Several reports are available in the literature on the in situ generation of silica in the different rubber matrices such as natural rubber (NR), isoprene rubber (IR), styrene butadiene rubber (SBR), polydimethylsiloxane (PDMS), ethylene propylene diene monomer rubber (EPDM), butadiene rubber (BR), acrylic rubber (ACM), and chloroprene rubber (CR) . However, research on nitrile rubber (NBR) filled with in situ silica is very limited.…”

“…In the solution method, dissolution of rubber in a proper solvent, followed by the addition of TEOS, water, and catalyst to the rubber solution is carried out. 12 Several reports are available in the literature on the in situ generation of silica in the different rubber matrices such as natural rubber (NR), [13][14][15][16][17][18][19] isoprene rubber (IR), [20][21][22] styrene butadiene rubber (SBR), [23][24][25][26] polydimethylsiloxane (PDMS), 27,28 ethylene propylene diene monomer rubber (EPDM), [29][30][31] butadiene rubber (BR), 11 acrylic rubber (ACM), 32 and chloroprene rubber (CR). 33 However, research on nitrile rubber (NBR) filled with in situ silica is very limited.…”

Influence of in situ -generated silica nanoparticles on EPDM morphology, thermal, thermomechanical, and mechanical properties

“…To solve this problem, the use of different silane coupling agents to improve rubber–filler interaction has been reported . An alternative and interesting method for overcoming the abovementioned difficulties is the application of in situ generation of an inorganic oxide (silica, alumina, titania, and others) in the rubber matrix by means of a sol–gel process.…”

Role of in situ generated silica for rubber science and technology

“…Excellent tensile properties were observed when the in situ silica content was increased. As well as SBR latex, NBR latex and NR latex were investigated. However, no study revealed the actual morphological characteristic features of in situ silica generated in the latexes because the precipitation technique followed by two‐roll milling was used, which can affect the in situ silica morphology.…”