Comparison of Characteristics of Natural Rubber Compounds with Various Fillers

Abstract

Natural rubber is the most frequently used elastomer worldwide due to its low prices, renewability, non-toxicity and excellent physical properties. Natural rubber is not used as such but in the form of mixtures which generally contain: fillers for reinforcement, plasticizers, crosslinking agents and other ingredients that confer different characteristics to the final product. Reinforcement of elastomers by incorporating fillers is a process of great practical and technological importance that greatly enhances the physical-mechanical properties of the composite material and reduces the cost price. The origin of such mechanical reinforcement has been linked to the interaction between the rubber and filler as well as the homogeneous dispersion of the filler within the polymer matrix. In natural rubber technology, knowledge of the conditions necessary to achieve more efficient natural rubber-filler interactions is improving continuously. The purpose of this article is to determine the influence of different types of mineral or organic fillers on the properties of natural rubber mixtures. The following were determined for the mixtures obtained: curing characteristics, hardness, elasticity, tensile strength, elongation at break and tear strength. The results indicate that both organic and inorganic fillers have led to improved physical and mechanical characteristics.

Degradation by Electron Beam Irradiation of Some Composites Based on Natural Rubber Reinforced with Mineral and Organic Fillers

“…In Table 2 are presented the recipes that were the basis of the obtaining of elastomeric materials further used in degradation by irradiation studies. Mixtures based on natural rubber (NR), maleic natural rubber (NR-gAM) and fillers were made by means of blending technique on a laboratory roll as in previous studies [1]. The maleated natural rubber (NR-g-AM), was obtained by roll mixing the natural rubber (NR) with 5 phr of maleic anhydride for synthesis and 0.75 phr of Perkadox 40.…”

“…The test specimen sheets of all composites were produced by compression molding at 165 • C for 24 min, according to the SR ISO 3417/1997. The optimum curing time (t90) of all spercimens was evaluated using an oscillating disk Monsanto rheometer [1] and the results obtained for control, NR-U, NR-C, NR-S and NR-H were 12.47, 5.45, 9.34, 6.22 and 6.81, respectively.…”

“…the SR ISO 3417/1997. The optimum curing time (t90) of all spercimens was evaluated using an oscillating disk Monsanto rheometer [1] and the results obtained for control, NR-U, NR-C, NR-S and NR-H were 12.47, 5.45, 9.34, 6.22 and 6.81, respectively. Scheme 1 shows the grafting mechanisms of maleic anhydride on the natural rubber chain and the obtaning of maleated natural rubber [30,31].…”

“…Due to its specific physical and chemical properties, non-toxicity, renewability and not least due to the low price, the natural rubber is the most used elastomer worldwide. A common industrial practice used for the enhancement of physical and mechanical properties of a composite material based on natural rubber consists of the incorporation of fillers in the polymer matrix [1]. Many fillers are used now in the rubber industry but, from its first use and until now, the carbon black remains the most important reinforcing agent even if causes pollution and gives the rubber a black color [2].…”