Degradation during Mixing of Silica-Reinforced Natural Rubber Compounds.

The optimal mixing conditions for silica-filled NR compounds dictate the need to proceed at a high temperature, i.e., 150 °C, to achieve a sufficient degree of silanization.

Dynamic Response and Molecular Chain Modifications Associated with Degradation during Mixing of Silica-Reinforced Natural Rubber Compounds.

Mixing silica-reinforced rubber for tire tread compounds involves high shear forces and temperatures to obtain a sufficient degree of silanization. Natural Rubber (NR) is sensitive to mastication and chemical reactions, and thus, silica-NR mixing encounters both mechanical and thermal degradation. The present work investigates the degradation phenomena during the mixing of silica-reinforced NR compounds in-depth.

Alleviating Molecular-Scale Damages in Silica-Reinforced Natural Rubber Compounds by a Self-Healing Modifier.

The property retentions of silica-reinforced natural rubber vulcanizates with various contents of a self-healing modifier called EMZ, which is based on epoxidized natural rubber (ENR) modified with hydrolyzed maleic anhydride (HMA) as an ester crosslinking agent plus zinc acetate dihydrate (ZAD) as a transesterification catalyst, were investigated. To validate its self-healing efficiency, the molecular-scale damages were introduced to vulcanizates using a tensile stress-strain cyclic test following the Mullins effect concept. The processing characteristics, reinforcing indicators, and physicomechanical and viscoelastic properties of the compounds were evaluated to identify the influences of plausible interactions in the system.

In Situ Modification of Polyisoprene by Organo-Nanoclay during Emulsion Polymerization for Reinforcing Natural Rubber Thin Films.

Nanoclay-modified polyisoprene latexes were prepared and then used as a reinforcing component in natural rubber (NR) thin films. Starve-fed emulsion (SFE) polymerization gives a higher conversion than the batch emulsion (BE), while the gel and coagulation contents from both systems are comparable. This is attributed to the SFE that provides a smaller average polymer particle size which in turn results in a greater polymerization locus, promoting the reaction rate.