Carbon black filled

Nitrile Rubber. Vulcanized mbber sheets of NBR and montmorillonite clay intercalated with Hycar ATBN, a butadiene acrylonitrile copolymer have been synthesized (36). These mbber hybrids show enhanced reinforcement (up to four times as large) relative to both carbon black-reinforced and pure NBR. Additionally, these hybrids are more easily processed than carbon black-filled mbbers. 

Examples of Cure Systems in NR, SBR, and Nitrile Rubber. Table 6 offers examples of recipes for conventional, semi-EV, and EV cure systems ia a simple, carbon black-filled natural mbber compound cured to optimum (t90) cure. The distribution of cross-links obtained is found ia Figure 9 (24). 

Fig. 9. Distribution of sulfur cross-links ia a carbon black-filled NR, where A is the conventional, B the semi-EV, and C the EV system.

In carbon black-filled natural mbber compound. 

Table 3. Properties of Carbon Black-Filled Natural Rubber Vulcanizates With Various Cure Systems ...

The Emerman model described in the previous section is hardly applicable to the carbon black-filled CCM as the black particles have sizes of hundreds angstrom and such a composite, compared with the molding channel size, may be considered as a homogeneous viscous fluid. Therefore, the polymer structure, crystallinity and orientation play an important role for such small particles. The above-given example of manufacture of the CCM demonstrates the importance of these factors being considered during processing of a composite material to and article with the desired electrical properties. 

FIGURE 1.13 Knotty tearing at the tip of an edge cut, 2.8 mm long, in a sheet of a carbon-black-filled natural rubber vulcanizate, broken in tension. (Reproduced from Hamed, G.R. and Park, B.H., Rubber Chem. TechnoL, 72, 946 (Figure 6), 1999. With permission.)... 

Rheographs of carbon black-filled vulcanizates cured at 160°C (second stage)... 

Pico Abrasion Data for Carbon Black Filled NR Compounds with or without QDI... 

FIGURE 18.1 Stress-strain relation of HAF carbon black-filled styrene-butadiene mbber (SBR). (From Chikaraishi, T., Koubunshi Gakkkai (Japan), No 25, Polymer Free Discussion, 1987.)... 

FIGURE 18.5 Equivalent models in carbon black-filled rubber aggregates (A), separated particles (B). 

Nevertheless, it is obviously shown in Figure 18.1 that the stress-strain curve of the filled mbber gives the clear stress upturn, thus its tensile strength becomes 30 MPa. Therefore, the fundamental question is what happens or what stmcture is produced in the carbon black-filled mbber under large extension, which newly generates the stress upturn. In the case of the fine carbon black-fiUed system, when carbon blacks are dispersed ideally, the carbon gel makes the continuous phase at the... 

Now, we show the relation between the ratio of 8 to Tq, 8/ro and the volume fraction of carbon black (p in Table 18.1, when the diameter of the hard particle (including carbon black, the GH layer and a little more contribution from the cross-links at the surface of particle) is tq and the distance between the hard particles is 8. In the carbon black-filled rubber (ip g 0.23-0.25), the fact that the stress of the filled system is 10-15 times larger than that of the unfilled rubber as shown in Figure 18.1 indicates that more than 90% of the stress of the system is supported by the supernetwork and the remainder of the stress results from the matrix rubber. In the present calculation, however, we can ignore the contribution from the matrix mbber. 

Mechanism of Compatibility of Molecular Slippage and Stress Upturn IN Carbon Black-Filled Rubbers... 

Now, we consider the interface of carbon black-filled mbber from the new interface model point of view. As we discussed before, the bonding is almost perfect in the three interfaces, between... 

FIGURE 18.18 Temperature dependence of the stress-strain relation in carbon black-filled natural mbber (NR). (From Fukahori, Y. and Seki, W Polymer, 33, 1058, 1992.)... 

Mechanism of the Great Hysteresis Energy of Carbon Black-Filled Rubber... 

The morphology of the agglomerates has been problematic, although some forms of network-like structures have been assumed on the basis of percolation behavior of conductivity and some mechanical properties, e.g., the Payne effect. These network stmctures are assumed to be determining the electrical and mechanical properties of the carbon-black-filled vulcanizates. In tire industries also, it plays an important role for the macroscopic properties of soft nano-composites, e.g., tear. 

Researchers [37] also compared the storage modulus of a 40 phr carbon black-filled compound and a 10 phr SWNT-NR nanocomposite. The different properties between carbon black- and SWNTs-filled NR nanocomposites can be explained in terms of two different filler morphology, particularly surface area, aspect ratio, and stmcture. It can be observed from Figure 28.22 that... 

FIGURE 29.6 Temperature profile of the phase angle tan 8 for a 75 phr N234 carbon black-filled versus a 75 phr silica/silane-reinforced green-tire compound. (From Wang, M.-J., Rubber Chem. Technol., 71, 520, 1998.)... 

J.L. Leblanc and C. Barres, Bound Rubber A Key Factor in Understanding the Rheological Properties of Carbon Black Filled Rubber Compounds, Rub. Div. Mtg, ACS, Chicago, IL, April 13-16, 1999, p. 70. 

J.L. Leblanc and B. Stragliati, An extraction kinetics method to study the morphology of carbon black filled mbber compounds, J. Appl. Polym. Sci., 63, 959-970, 1997. 

Physical properties of carbon black-filled EPR and EPDM elastomers have been found to be comparable with the suUur-cured analogues [372]. Aromatic oils increase the optimum dose requirement for these compounds due to the reaction of the transient intermediates formed during radiolysis of the polymer with the oil as well as energy transfer which is particularly effective when the oil contains aromatic groups. The performance and oxidative stability of unfilled EPDM as well as its blend with PE [373], and the thermal stabdity and radiation-initiated oxidation of EPR compounds are reported by a number of workers [374,375]. 

Chemicals like polyorthoaminophenol, diphenylamine in small amounts have been found to decrease the yield of cross-linking [388]. The tensile strength of the carbon black-filled polychloroprene compounds has been found to be comparable to the conventional thermally cured one. The physical properties [389] have been observed to improve on adding cross-linking promoters like A,A -hexamethylene-bis-methacrylamide into the polymer matrix. 

Table 2.4) or proprietary test methods. Forrest [38] has listed 94 international rubber analysis standards (ISO) and 20 ISO standards in preparation referring to latices, carbon-black-filled compositions, raw and compounded rubbers. 

Table 6.40 Optimal methods for detection of organic additives in carbon-black-filled rubber vulcanisates...

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