Kinetics of selective wetting of carbon nanotubes (CNT) in rubber blends

• Applicant: Dr.-Ing. Hong Hai Le
• Subject Area: Plastics Engineering
• Term: from 2013 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 239403382

In order to achieve defined technical properties of tire tread compounds, in practice, blends of different rubbers are produced, usually. Addition of carbon nanotubes (CNT) in polymer blends is a promising way to combine the well-known advantages of polymer blends with conductivity/ antistatic properties and other reinforcement potential of CNT. The improvement of the CNT-rubber interphase can be preferably realized by the chemical modification of the CNT surface and/or functionalization of the rubber matrix. Recently, the use of ionic liquids (IL) as potential surface modifier for CNT in rubber composites has been frequently investigated. In contrast to the chemical modification the physical cation-pi bondings between IL molecules and CNT surface can be dissolved and replaced by the CNT-rubber bondings under thermodynamic driving forces during the mixing process that leads to a completely different wetting behavior of the CNT. Thereby, the specific adjustment of the composite performance by controlling the filler-rubber interphase becomes very difficult, in particular, in multiphase rubber blends. It lacks a consistent method for the quantitative characterization of the development of the structure and composition of the filler-rubber interphase during the mixing process of filled rubber blends so far.From scientific and technical aspects the submitted research project focuses on the further development of the wetting concept and Z-model, which have been established in previous works for CB and silica filled rubber compounds, to describe the kinetics of the selective CNT wetting in binary rubber blends. The formation of the filler-rubber interphase will be qualitatively and quantitatively characterized by taking into consideration the presence of ionic liquid. The elucidation of the relationship between the molecular structure of blend components, mixing parameters, and the selective CNT wetting, dispersion and distribution, as well as the physical properties of filled rubber blends is the target of the project. The aim of the project to establish knowledge of the selective wetting behavior of CNT in rubber blends are scientifically new and go significantly beyond the state of the art. The comprehensive knowledge and experiences of the host institute (IPF Dresden) in chemical and physical modification of polymers and fillers in material development in combination with the competent of the applicant in the characterization and description of structure development in the mixing processes of filled rubber blends complement one another in an ideal way. Their previous collaboration represents a basic for the success of the project.

• DFG Programme: Research Grants
• Participating Person: Dr. Sven Henning