Comparison of Reinforcing Efficiency between Calcium Carbonate/Carbon Black and Calcium Carbonate/Silica Hybrid Filled Natural Rubber Composites

Abstract

The present research aimed to develop natural rubber (NR) hybrid composites reinforced with calcium carbonate/carbon black (CC/CB) and calcium carbonate/silica (CC/SC). The influence of CC/CB and CC/SC with various filler ratios (120/0, 90/5, 60/10, 30/15 and 0/20) on cure characteristics and mechanical properties of the vulcanizates was investigated and their reinforcing efficiency was compared. It has been found that incorporation of CB in the hybrid filler decreases the scorch time and cure time but increases crosslink density, whereas the incorporation of silica showed cure retardation. As CB or SC content increases, stiffness, tensile strength and tear strength increase, while elongation at break and compression set decrease. Scanning electron microscopy studies also reveal poor filler dispersion and poor adhesion between filler particles and matrix in the vulcanizates with increasing in CC content in a weight filler ratio which causes inferior mechanical properties. Incorporation of CB or SC content enhanced the mechanical properties of the vulcanizates, where CC/CB hybrid system exhibited higher reinforcing efficiency compared with CC/SC hybrid system.

Mechanical properties and microstructure of hybrid vulcanized natural rubber filled with carbon black and nano-CaCO₃ from <i>Achatina achatina</i> Shells

“…This is because, at higher proportion of the synthesized nanoparticles in hybrid composites, the interfacial bonding between the fillers reduced and agglomeration of the nano-CaCO3 became dominant. The results obtained in the hybrid composites are also in agreement with literature [9]. The significant improvement in the strength of the hybrid composites is due to the synergistic effects of the two fillers which imparted higher filler dispersion ensuring effective transfer of stress from matrix to filler as well as higher cross-linking density which enhanced the strength [8] [20].…”

“…The significant improvement in the strength of the hybrid composites is due to the synergistic effects of the two fillers which imparted higher filler dispersion ensuring effective transfer of stress from matrix to filler as well as higher cross-linking density which enhanced the strength [8] [20]. In hybrid composites, the fillers combine their good properties to enhance the properties of the composites [9]. Hybrid filled rubber components are applied in tyre treads, sidewalls, inner liner, conveyor belts, and bumper strips [9].…”

“…In hybrid composites, the fillers combine their good properties to enhance the properties of the composites due to the synergistic effects of two fillers resulting to higher filler dispersion and cross-linking densities [8][9]. Hybrid filled rubber components are applied in tyre treads, sidewalls, inner liner, conveyor belts, and bumper strips [9].…”

Mechanical and rheological properties of partial replacement of carbon black by treated ultrafine calcium carbonate in natural rubber compounds

“…Mostly rubber products as shoes, soles, sandals, etc. Employed commercial reinforcement llers to improve mechanical properties as silica [1][2][3], carbon black [4][5][6] or even to reduce the rubber mass, loading with calcium carbonate [7,8], kaolin [9,10], asphalt [11], grits waste [12], sludge ash [13] and bio composites [14,15]. The size and shape homogeneity are usually considered, improving surface adhesion in the polymer matrix [7] and, enhancing the reinforcement effect.…”

Performance of Nano- and Microcalcium Carbonate in Uncrosslinked Natural Rubber Composites: New Results of Structure–Properties Relationship

“…However, there are some fillers that can be used as non- or semireinforcing fillers (such as calcium carbonate, clay, talc, etc.) for either reducing cost or improving mechanical properties [ 15 ].…”