Nanocomposites of styrene–butadiene rubber and synthetic anatase obtained by a colloidal route and their photooxidation

Abstract

Photodegradable styrene-butadiene rubber (SBR)/TiO 2 nanocomposites were prepared by a colloidal route through the simple mixing of a commercial polymer latex and synthetic anatase nanoparticles. Stable colloids of pure anatase TiO 2 nanoparticles with an average diameter of 7 nm were prepared by a solvothermal route from the hydrolysis of titanium alkoxide by hydrogen peroxide in the presence of oleic acid. The photocatalytic degradation of the SBR-TiO 2 nanocomposites was carried out in ambient air at room temperature under a UV lamp and was monitored by Fourier transform infrared and UV-visible spectroscopies and differential scanning calorimetry. The results show that the SBR-TiO 2 nanocomposites were photocatalytically degraded under UV light, which indicate that the butadiene chains in the nanocomposite were oxidized during UV irradiation. Thermal analysis measurements indicated that crosslinking reactions occurred. The presence of anatase TiO 2 nanoparticles was found to accelerate the photocatalytic process, and the degradation mechanism was similar to that of the pure SBR polymer.

Study of the effect of rutile/anatase TiO2 nanoparticles synthesized by hydrothermal route in electrospun PVA/TiO2 nanocomposites

“…Figure 6(B) shows that the mass loss was negligible, contrary to the result in our previous study,6 in which a TiO 2 anatase loading promoted a severe mass loss, especially in the first degradation times. Arantes et al30,31 also observed a similar degradation effect when loading styrene–butadiene rubber with synthetic TiO 2 anatase. The current result is very important, as it shows that the rutile TiO 2 synthesized, despite being in a mixture with some anatase, was effective in modifying the UV absorption behavior of PVA, without negatively affecting the PVA stability.…”

Comparison of the nanoparticles performance in the photocatalytic degradation of a styrene–butadiene rubber nanocomposite

“…By transmission electron microscopy, they observed some lamellae curved and adhered on the surface of the polymer colloidal particles due to the presence of counter ions clustered between them. The existence of this interaction is the key point to obtain uniform nanocomposites from a dispersion of inorganic nanoparticles and polymeric macromolecules through solvent elimination 11,12…”

“…In our previous work, we studied the effect of titanium dioxide nanoparticles in the mechanism of polymer photodegradation 11,12. Thus, we are now studying the influence of different nanoparticles on the photodegradation of the SBR nanocomposite matrix.…”

“…All nanocomposites and pure SBR films were exposed to UV light for different time intervals up to 96 h, and their attenuated total reflectance infrared spectra are shown in Figure 2. It is known that titanium dioxide is an efficient photocatalyst capable of generating reactive oxygen species that degrade the polymer 11,13–15. When semiconductor oxides such as TiO 2 or ZrO 2 are irradiated with photons of energy equal to or greater than its energy gap, electrons in the conduction band can generate holes or vacancies in the valence band that are responsible by the oxidation reaction 16–18.…”

Investigation of polymer‐based composites by laser desorption/ionization study of their photo‐oxidative aging

“…5,16,28 When an organic (a pigment, for example) or an inorganic filler (titanium dioxide, for example) is added to the polymer, the aging processes are significantly modified but the final products are generally unchanged. [15][16][17][29][30][31][32] The absorption of a UV photon by titanium dioxide ensures the formation of mobile electrons and holes, which interact with molecular oxygen, hydroxyl anions and water adsorbed at the surface of the TiO 2 particles to form reactive oxygen species (ROS). ROS may also be generated by the interaction of the S 1 excited state of an organic compound with O 2 or H 2 O.…”