Epoxidized natural rubber /silica

FIGURE 3.12 Morphology of mbber-silica hybrid composites synthesized from solution process using different solvents (a) and (b) are the scanning electron microscopic (SEM) pictures of acrylic rubber (ACM)-silica hybrid composites prepared from THF (T) and ethyl acetate (EAc) (E) and (c) and (d) are the transmission electron microscopic (TEM) pictures of epoxidized natural rubber (ENR)-siUca hybrid composites synthesized from THF and chloroform (CH). (From Bandyopadhyay, A., De Sarkar, M., and Bhowmick, A.K., J. Appl. Polym. Sci., 95, 1418, 2005 and Bandyopadhyay, A., De Sarkar, M., and Bhowmick, A.K., J. Mater. Sci., 40, 53, 2005. Courtesy of Wiley InterScience and Springer, respectively.)... 

FIGURE 3.16 Morphology and visual appearance of acrylic rubber (ACM)-silica and epoxidized natural rubber (ENR)-silica hybrid composites prepared from different pH ranges (a) transmission electron microscopic (TEM) picture of ACM-siUca in pH 1.0-2.0, (b) scanning electron microscopic (SEM) picture of ACM-siUca in pH 5.0-6.0, (c) SEM image of ACM-siUca in pH 9.0-10.0, (d) TEM picture of ENR-silica in pH... 

FIGURE 3.19 Comparative Kraus plots of acrylic rubber (ACM)-silica and epoxidized natural rubber (ENR)-silica hybrid nanocomposites at different in situ silica concentrations. (From Bandyopadhyay, A., De Sarkar, M., and Bhowmick, A.K., J. Polym. Sci., Part B Polym. Phys., 43, 2399, 2005. Courtesy of Wiley InterScience.)... 

Silica reinforcement using the sol gel technique on epoxidized natural rubber 25 mol% (ENR 25) has been reported. ENR was first pre-ciued with 3-aminopropyltriethoxysilane (APS). APS was mixed into ENR and the ENR-APS mixture was cured at 180 °C to produce pre-ciued rubber sheets with tensile properties much lower than those of normally ciued rubber vulcanizates. The crosslinking of ENR utilizing the epoxy groups as crosslinking sites using amine functional groups catalysed by bisphenol A has been established. The ENR-APS network is shown in Scheme 7.2. 

As compared to natural rubber, epoxidized grades of natural rubber show improved reinforcement with silica without any coupling agent. Radial tyre tread prepared using formulations based on natural rubber with epoxide... 

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