Cure Characteristics and Rheological Properties of Modified Kaolin-natural Rubber Composites

Abstract

Aim: This study seeks to examine the cure characteristics and rheological properties of modified kaolin -Natural rubber vulcanizates. Methodology: Metal salt of rubber seed oil (RSO-Na) was used to modify kaolin and was then introduced into Natural Rubber (NR) by melt intercalation to produce vulcanizates mixed with various compositions of pristine and modified kaolin (2 -10 Parts per hundred rubbers). Results: Characterization of the modified kaolin using X-ray diffraction revealed increase in d-spacing from 7.15 to 14 Ǻ. Torque minimum (M L ), torque maximum (M H ) which are correlated with hardness increased with increasing organoclay loading. The storage modulus (G 1 ), loss modulus (G 11 and complex viscosity (Ƞcomplex) increased with increase in modified kaolin thus showing remarkable improvements of the vulcanizates. Conclusion:The results from the study indicate that the modified filled kaolin has a dramatic improvement on the NR composite compared to the pristine.

Rheological properties and curing features of natural rubber compositions filled with fluoromica ME 100

“…Data of Figure 1 show that above 5 phr mica has a significant influence on the complex viscosity of the compositions, corroborating the results for minimum torque (M L ) [18][19][20][21][22] . According to Chen et al [20] , surface adhesion between the filler and the matrix hinders the flow of elastomeric compositions as a result of the partial formation of phase interactions [19,20] .…”

“…Maximum torque (M H ), Minimum Torque (M L ), Curing Time (T 90 ) , Pre-Curing Time (T s1 ) and Curing Rate Index (CRI) were taken and/or calculated from the elastic torque plot (S') versus time supplied by the RPA equipment [19][20][21][22] .…”

“…According to Chen et al [20] , surface adhesion between the filler and the matrix hinders the flow of elastomeric compositions as a result of the partial formation of phase interactions [19,20] . In this way, data of Figure 1 allow to estimate the NR-ME 100 mica interactions.…”

The potential of kaolin as a reinforcing filler for rubber composites with new sulfur cure systems

“…5 In a study, modified kaolin was introduced into NR and cured at 140 o C for 10 min to produce some composites. 35 The interspacing between the kaolin layers measured by XRD was from 7 to 14 A o . The presence of the modified kaolin resulted in increase in the torque value caused by the formation of a higher number of crosslinks, which was attributed to the confinement of the rubber chains within the silicate galleries and hence to better interaction between the filler and the rubber.…”

“…35 Metal salt of rubber seed oil (RSO-Na) was used to modify kaolin and then was introduced into NR. Rubber composites mixed with various compositions of pristine and modified kaolin (2-10 phr) were then prepared and tested.…”