화학공학소재연구정보센터
Polymer Engineering and Science, Vol.61, No.3, 906-917, 2021
Effect of pre-mastication on dispersion of nanoclay in presence of carbon black in an inner liner compound: Studies on physicomechanical and functional properties
The present study demonstrates the use of "pre-mastication" technique for getting higher dispersion of organoclay, Cloisite 15A, in an inner liner compound based on 70:30 bromobutyl and natural rubber blend, in presence of higher concentration of carbon black (60 phr) for the improvement of functional properties like fatigue cut growth and air permeability resistance. Studies have showed that the organoclay was almost equally distributed within the blend both in absence as well as in presence of carbon black. The vulcanization curve showed a marked increase in cure acceleration as well as a significant rise in the maximum torque value because of higher crosslinking aided by the participation of the quaternary amine present in Cloisite 15A; however, in the carbon black loaded compound, the cure acceleration was not so pronounced because of engaging interaction between amine and functional groups of carbon black. The microscopic study revealed a good dispersion of Cloisite 15A within the elastomer blend- in presence of carbon black. The anisotropic platelets of Cloisite 15A and carbon black particles jointly formed "nano units", which occluded a portion of elastomer segments vis-a-vis partial intercalation within the clay gallery. Such a reinforcing model was instrumental in improving the physicomechanical and functional properties under static and dynamic conditions. The organoclay displayed a much-improved properties at 2 and 4 phr doses in presence of 60 phr carbon black because of formation of enough "nano units" while deterioration was observed at 6 phr dose due to clay aggregation. Based on the results obtained on functional properties it was concluded that the 4 phr of organoclay compounded in "pre-mastication" mode delivered the best improvement and thus it was recommended for future up-scaling study.