DEVELOPMENT OF HIGH PERFORMANCE RUBBER COMPOSITES FROM ALKOXIDE-BASED SILICA AND SOLUTION STYRENE–BUTADIENE RUBBER

ABSTRACT The solution SBR and silica-based composites are prepared by hydrolysis of tetraethylorthosilicate in the presence of an organic solution of SBR and n-butylamine as catalyst. Further addition of bis[3-(triethoxysilyl)propyl]tetrasulfide, a silane coupling agent, improves the performance and properties of the composites. All the results are compared with commercial precipitated silica at similar loading conditions. The generated silica particles from this alkoxide route resulted in lower Mooney viscosity of the compound and showed less filler flocculation compared with standard commercial precipitated silica in reference compounds. A detailed dynamic mechanical study also indicated that alkoxide silica in model tire compounds could offer a lower rolling resistance and a higher wet skid resistance compared to the reference. Other properties such as heat build-up, rebound resilience, and hysteresis loss were found to be very promising for alkoxide silica composites, too. The silica particles (aggregated) developed by the alkoxide method were relatively large (∼150–200 nm) compared with the primary particles of precipitated commercial silica. The synthesis of sol–gel silica particles in presence of the polymer allowed for the trapping of some polymer molecules inside the filler aggregates and therefore offers exceptional mechanical reinforcement of the rubber.

Synthesis of Tetragonal BaTiO3 Powders via Alkoxide Method Assisted by Diethanolamine

The BaTiO3 precursor was prepared by alkoxide method, in which barium hydroxide octahydrate and butyl titanate were chosen as the Ba and Ti sources, and diethanolamine (DEA) as the polymerizing agent respectively. In order to determine the synthesis parameters of the target product, the phase transition process of the precursor with temperature increasing was investigated by TG-DTA. The effect of calcination temperature, the dosage of DEA and calcination time on the phase compositions and crystal structure of the synthesized samples were investigated by XRD. The results indicate that DEA can promote the formation of tetragonal BaTiO3 effectively, and the high-purity tetragonal BaTiO3 was obtained by heat treatment of the precursor at 1100°C for 3h with 1mL DEA dosage.

Novel Method to Synthesize Ceria Coated Silica particles

Monodispersed ceria coated silica particles were prepared by a new type of ceria precursor. The ceria precursor was synthesized by alkoxide method, which employs ethanol as solvent. The synthesized particles were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was found that well-crystalline ceria coatings were deposited on the surface of the silica particles without post-heat treatment. In addition, the coated particles prepared by a new precursor were uniformly dispersed without the formation of hard aggregate as compared to those obtained by conventional method.