Linear-nonlinear dichotomy of the rheological response of particle-filled polymers

• Published in: Journal of applied polymer science Vol. 131; no. 19; pp. np - n/a
• Main Authors: Randall, Amy M., Robertson, Christopher G.
• Format: Journal Article
• Language: English
• Published: Hoboken, NJ Blackwell Publishing Ltd 05.10.2014; Wiley; Wiley Subscription Services, Inc
• Subjects: Applied sciences; Automotive components; Composites; Correlation analysis; Dichotomies; elastomers; Exact sciences and technology; Fillers; Forms of application and semi-finished materials; Materials science; nanoparticles; Polymer industry, paints, wood; Polymers; Rheology; Rubber; Strain; Technology of polymers; viscosity and viscoelasticity; Dispersion reinforced material; Processability; viscosity and viscoelasticity; Silica; Composite material; Property formulation relationship; Shear viscosity; nanoparticles; rubber; Nanocomposite; Technological properties; Diene polymer; SBR; Carbon black; rheology; Mechanical properties; Organic silane; Natural rubber; Nitrile rubber; Chloroprene polymer; Functional polymer; Coupling agent; Polymer filler interaction; Tyre; elastomers; Butadiene polymer; Non linear viscoelasticity; Non linear properties; Isoprene polymer; Rheological properties
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.40818

ABSTRACT Novel nanoparticles, polymer‐particle coupling agents, and functionalized polymers are being developed to enhance the performance of particle‐reinforced polymer systems such as advanced rubber compounds for automobile tires. Understanding the complex rheological behavior of rubber is critical to providing insights into both processability and end‐use properties. One unique aspect of the rheology of filled elastomers is that the incorporation of particles introduces a hysteretic softening (Payne effect) at small dynamic strains. This study demonstrates that this nonlinear viscoelastic behavior needs to be considered when attempting to correlate steady shear response (Mooney viscosity) to oscillatory shear measurements from test equipment such as the Rubber Process Analyzer (RPA). While a wide array of unfilled gum elastomers show good correlation between Mooney viscosity and dynamic torque from the RPA at all of the strain amplitudes used, rubber compounds containing silica and carbon black particles only exhibit good agreement between the two measures of processability when the oscillatory strain amplitude is high enough to sufficiently break up the filler network. Other features of the filler network and its influence on nonlinear rheology are considered in this investigation, including the effects of polymer–filler interactions on filler flocculation and the use of Fourier transform rheometry to illustrate the “linear‐nonlinear dichotomy” of the Payne effect. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40818.