Performance of binary accelarator system on natural rubber compound

Ihda Novia Indrajati,Indiah Ratna Dewi

doi:10.20543/mkkp.v34i2.4049

Abstract

Accelerator system provides different response onto the rubber compound, and in turn influences its final properties. Accelerators, such as 2,2'-Dithiobis (benzothiazole) (MBTS), N-Cyclohexylbenzothiazole-2-Sulfenamide (CBS) and diphenyl guanidine (DPG), has been selected for the study. Response of paired accelerator, MBTS/DPG and CBS/DPG in various ratio, on natural rubber (NR) compound was evaluated. Rheological properties and cure characteristics of the compounds were analyzed using Mooney viscometer and moving die rheometer (MDR) typically. Results findings showed that incorporation of DPG into the system has increased the viscosity of the compound and effected the molecular weight during the process. Further, the addition of DPG also shortened the induction period by reducing the scorch time (ts2) and decreasing the cure time (t90). Binary paired accelerator resulted in poor flow characteristic as a result of strong domination of elastic element. In general, the CBS-based system provided more balance characteristic than those of MBTS-based.

Highlights

Rubber is converted to a valuable product with excellent properties through several processing steps, i.e. compounding, forming and vulcanization
Accelerator type affects the Mooney viscosity, in which single accelerator (MBTS or CBS alone) provides lower Mooney viscosity compared to paired accelerators
MBTS-based systems result in higher Mooney viscosity than of CBS-based systems

Summary

Introduction

Rubber is converted to a valuable product with excellent properties through several processing steps, i.e. compounding, forming and vulcanization. All of the curve parts of MBTS/DPG systems are laid on below the transition line (Figure 10) that exhibits strong domination of elastic element since at the beginning. This could generate problems during compound processing. Poor flow characteristic affects the possibilities of rejected product caused by uneven mold filling It negatively impacts in extrusion process due to increased die swell. The rubber compound will be easier to flow and broaden the S”/S curve This finding is not observed when CBS/DPG is used (N5 and N6) because of similar resulted crosslink density (Figure 4b)

Methods

Results

Conclusion