Effects of accelerators on the cure characteristics and mechanical properties of natural rubber compounds

Abstract

The effects of different accelerators on the cure characteristics and mechanical properties of sulphur-cured natural rubber (NR)-based compounds are investigated. Three accelerator systems, with mercaptobenzothiazole disulphide (MBTS) as primary accelerator and diphenylguanidine (DPG) and Zn-2-mercaptobenzothiazole (ZMBT) as secondary accelerators, were incorporated into a premixed NR compound referred to an industrially used rubber mat formulation by using the melt mixing method. The cure characteristics, rubber crosslink density and mechanical properties were the focus in the present study. It is observed that the synergistic effect of the MBTS/DPG combination imparts the shortest scorch time, highest cure rate and highest crosslink density compared with the MBTS/ZMBT and MBTS/ZMBT/DPG combinations. Mechanical tests indicate that the tensile strength and modulus of MBTS/DPG are enhanced owing to improved cure activation in initiating sulphuric crosslinking, but the tear strength is decreased compared with the others. This study demonstrates that the MBTS/ZMBT/DPG system is the most effective in enhancing tear strength by 4.5 % compared with MBTS/DPG system, as well as other mechanical properties. Analyses on tear behaviours and scanning electron microscope (SEM) micrographs of the fractured surfaces of tear test samples correspond well with the results of tear strength.

Comparative study among TMTD, TBzTD, and ZBEC accelerators in isobutylene‐isoprene elastomer vulcanization

“…Oliveira and Soares and Ahsan et al . reported that such a combination, in adequate proportions, can significantly improve the scorch time, vulcanization characteristics, and final mechanical properties of the material.…”

“…In addition, the vulcanization kinetics may be altered by the use of accelerators, which are intended to improve the efficiency of crosslinks that occur during the vulcanization step . Frequently, rubber formulations contain a binary accelerator system in order to improve the scorch time, vulcanization characteristics and final mechanical properties of the material . The types of crosslinks in a given compound might notably affect their physical properties.…”

Effects of reinforcing arrangement of kenaf fibres into unsaturated polyester for improved properties

“…In addition, environmental sustainability and reduced demand of polymer are also considered as significant impacts of using them with polymer matrices [9][10][11]. There are drawbacks of using NFs, which are also found in the literature as reported by different researchers.…”

The Blending of EPDM/NR with Maleic Anhydride as Compatibilizer: Comparing the Effect of Accelerators on Cure Characteristic and Mechanical Properties

“…Primary accelerator is commonly reacted with another faster accelerator type that becomes the secondary accelerator. The cure characteristics and the processing safety of the compounds are strongly influenced by the accelerators [9][10][11].…”

“…TMTD, ultra-fast accelerator, can be used as a primary or secondary accelerator. TBBS is classified as a delayed action accelerator that involves a long vulcanization process [10][11]. Accelerators used in this study are shown in Table 1.…”