Samayamutthirian Palaniandy

The Effects of Silanized Ultrafine Silica on the Curing Characteristics, Tensile Properties, and Morphological Study of Natural Rubber Compounds

The curing characteristics, tensile properties, and morphological of untreated and silanized ultrafine silica filled natural rubber with bis[(3-triethoxysilylpropyl)tetra sulfide] (Si-69) were studied. The results show the scorch time and cure time of silanized silica was shorter as compared to untreated silica at the same filler loading. On tensile properties, the presence of Si-69 had improved the tensile strength, elongation at break, tensile modulus and hardness of ultrafine silica after silanized silica show higher values compared to untreated silica. The scanning electron microscopy study indicated that silanized silica has better filler-rubber interaction compared to untreated silica.

Comparison of Commercially Available Silica and Value-Added Silica as a Filler in Rubber Compounds

The effect of filler loading and size on commercially available silica (Vulcasil C) and value added silica (ultrafine) as filler in SMR L grade natural rubber were studied. Vulcasil C with particle size ranged from 10 µm–20 µm whilst ultrafine (1 µm–3 µm) was loaded in SMR L compound at 4 different loadings. The curing characteristics, tensile properties and swelling behavior were studied. At similar filler loading, ultrafine-filled vulcanizates exhibited shorter scorch time and cure time. It also shows higher tensile strength and elongation at break up to 20 phr filler loading and exhibit lower swelling ratio compared to Vulcasil C-filled vulcanizates.