Blending of NR/BR/EPDM by reactive processing for tire sidewall applications: Part I - Preparation, cure characteristics and mechanical properties

Kannika Sahakaro, N. Naskar, Nityananda Naskar, Jacobus W.M. Noordermeer, Rabin Datta

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18 Citations (Scopus)


EPDM incorporated into blends of natural rubber/butadiene rubber (NR/BR) improves ozone resistance. In this work, the inferior mechanical properties of NR/BR/EPDM blends generally obtained by conventional straight mixing are overcome by utilizing a reactive processing technique. The entire amount of curatives, based on a commonly employed accelerator N-cyclohexyl-2-benzothiazole sulfenamide (CBS) and sulfur, is first added into the EPDM phase. After a thermal pretreatment step tuned to the scorch time of the EPDM phase, the modified EPDM is mixed with premasticated NR/BR. The reactive blend vulcanizates show a significant improvement in tensile properties: tensile strength and elongation at break, as compared to those prepared by straight mixing, in both gum and carbon black-filled blends. The increase of tensile properties in gum and filled reactive blend vulcanizates does suggest that the reactive processing technique leads to more homogeneous blends due to, either a better crosslink distribution, or more homogeneous filler distribution, or both.
Original languageUndefined
Pages (from-to)2538-2546
Number of pages8
JournalJournal of applied polymer science
Issue number4
Publication statusPublished - 2007


  • reactive processing
  • IR-72335
  • METIS-246537
  • Tire sidewall
  • Blends

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