Influence of magnesium carbonate loading on the compound properties of polychloroprene, natural rubber, and their blends

Abstract

The effect of magnesium carbonate (MgCO 3 ) loading on the compound properties of polychloroprene (CR), natural rubber (NR), and their blends was investigated. The studied properties included Mooney viscosity, cure characteristics, and degree of filler-filler interaction. In addition to MgCO 3 loading, the effect of the blend ratio on such properties was simultaneously determined. The results reveal that, regardless of the rubber type and blend ratio, increasing MgCO 3 loading resulted in not only an increase in the compound viscosity, but also in the enhancements of the cure rate and state of cure. However, the effect of MgCO 3 loading on the overcured behavior was strongly dependent on the rubber type and blend ratio. For CR, the presence of MgCO 3 accelerated postcuring, whereas the opposite results were found for NR, in which the reversion rate was promoted. For CR/NR blends, a plateau behavior was obtained at a 50/50 blend ratio, where the degrees of postcuring and reversion were counterbalanced. The results also reveal that when MgCO 3 was loaded at low concentrations ( 20 phr), the degree of filler-filler interaction was very low and had no significant effect on the compound properties.

MgO and ZnO as reinforcing fillers in cured polychloroprene rubber

“…It is suggested that the magnitude of the torque difference (M H À M L ) can be used as an indication of crosslink density in rubber cured specimens, i.e., the greater is the torque difference magnitude, the higher is the crosslink density. [22][23][24][25] Determination of the crosslink density by the torque difference is confirmed by the comparison shown in Figure 7. The trends of torque difference and crosslink density results are in good accordance suggesting the applicability of torque difference as an indication of crosslink density.…”

“…It is suggested that the magnitude of the torque difference ( M H − M L ) can be used as an indication of crosslink density in rubber cured specimens, i.e., the greater is the torque difference magnitude, the higher is the crosslink density 22–25. Determination of the crosslink density by the torque difference is confirmed by the comparison shown in Figure 7.…”

Enhancement of rubber–carbon black interaction by amine‐based modifiers and their effect on viscoelastic and mechanical properties

“…As reported elsewhere, the decrease in magnitude of Δ G ′ is used as an implication of reduction in filler–filler interaction and thus CB percolation. Such Δ G ′ reduction would then lead to an improvement in filler dispersion degree 21, 25. Thus, as evidenced from Figure 6, both modifiers gave decreasing in Δ G ′ of the CB‐M/B implying the enhancement in the degree of filler dispersion.…”

Study on the effect of virgin and recycled chloroprene rubber (vCR and rCR) on the properties of natural rubber/chloroprene rubber (NR/CR) blends

“…Das et al [32] explained a similar factor for the delayed action in the curation process between CR and ethylene-propylenediene terpolymer that is due to the reduction of unsaturated sites in the blends. Sae-Oui et al [33] and Chokanandsombat and Sirisinha [34] described chlorine (Cl) atoms in the CR molecules to be the cause of the double bonds in CR, which were not reactive towards the sulfur vulcanization. The delayed nature of CR due to the decrease of unsaturated chains and different reactive sites consequently caused longer t s2 and t 90 in these rubber blends.…”