Enhanced apparent payne effect in a gum vulcanizate at low temperature approaching glass transition

• Published in: Polymer engineering and science 2003-08, Vol.43 (8), p.1512-1521
• Main Authors: Pan, Xiao-Dong, Kelley, Edward D.
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical reactions and properties; Crosslinking, vulcanization; Exact sciences and technology; Organic polymers; Physicochemistry of polymers
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.10128

For a vuleanized elastomer compound containing no filler, variation of dynamic moduli with strain was examined in the transition zone approaching glass transition at 0.1, 1, 10, and 15 Hz. In the complete absence of filler‐filler/filler‐polymer interactions, the nonlinearity in dynamic moduli becomes enhanced upon approaching glass transition regardless of testing frequency. Under the test protocol employed, the extraordinary nonlinearity at 10 Hz and 15 Hz is shown to be associated with a spectacular shear‐heating event. At 10 Hz and −19°C, a pronounced yielding‐like peak in the in‐phase stress component emerges at small strain (< 2%) during testing of increasing strain. However, the corresponding temperature rise here is only about 0.4°C. Interestingly, at or above 0°C, no such peak in the in‐phase stress component emerges for compounds filled with reinforcing filler above the percolation threshold. Discussion is also made relating the observations to the sliding friction of rubber materials.