Poly(acrylonitrile-co-butadiene) as polymeric crosslinking accelerator for sulphur network formation

Sakrit Hait; Juan López Valentín; Antonio González Jiménez; Pilar Bernal Ortega; Anik Kumar Ghosh; Klaus Werner Stöckelhuber; Sven Wießner; Gert Heinrich; Amit Das

doi:10.1016/j.heliyon.2020.e04659

Poly(acrylonitrile-co-butadiene) as polymeric crosslinking accelerator for sulphur network formation

Heliyon. 2020 Aug 26;6(8):e04659. doi: 10.1016/j.heliyon.2020.e04659. eCollection 2020 Aug.

Authors

Sakrit Hait^{1

2}, Juan López Valentín³, Antonio González Jiménez⁴, Pilar Bernal Ortega³, Anik Kumar Ghosh^{1

2}, Klaus Werner Stöckelhuber¹, Sven Wießner^{1

2}, Gert Heinrich^{1

2}, Amit Das¹

Affiliations

¹ Leibniz-Institut für Polymerforschung Dresden e.V., D-01069 Dresden, Germany.
² Technische Universität Dresden, D-01069 Dresden, Germany.
³ Institute of Polymer Science and Technology (ICTP-CSIC), Madrid, Spain.
⁴ Materials Science and Engineering Area, Rey Juan Carlos University, C/Tulipán s/n, 28933, Móstoles, Madrid, Spain.

Abstract

The major controlling factors that determine the various mechanical properties of an elastomer system are type of chemical crosslinking and crosslink density of the polymer network. In this study, a catalytic amount of acrylonitrile butadiene copolymer (NBR) was used as a co-accelerator for the curing of polybutadiene (BR) elastomer. After the addition of this copolymer along with other conventional sulphur ingredients in polybutadiene compounds, a clear and distinct effect on the curing and other physical characteristics was noticed. The crosslinking density of BR was increased, as evidenced by rheometric properties, solid-state NMR and swelling studies. The vulcanization kinetics study revealed a substantial lowering of the activation energy of the sulphur crosslinking process when acrylonitrile butadiene copolymer was used in the formulation. The compounds were also prepared in the presence of carbon black and silica, and it was found that in the carbon black filled system the catalytic effect of the NBR was eminent. The effect was not only reflected in the mechanical performance but also the low-temperature crystallization behavior of BR systems was altered.

Keywords: Acrylonitrile butadiene; Activation energy; Crosslinking accelerator; Crystallization; Curing kinetics; Low-temperature; Materials chemistry; Materials science; Polybutadiene; Solid state NMR; Sulphur network.