Carbon black loading

Mamzen Oil Co. has developed various Ziegler-Natta catalysts that can produce poly(butadiene-i //-prop5iene) (PBR) (78). PBR shows tack (self-adhesion) and green (unvulcanized) dynamic properties superior to those of BR and EPDM. Carbon black-loaded vulcanizates can be compounded to give high strength and elongation at break (79,80). PBR can also be covulcanized with SBR, BR, and EPDM. 

Flexible tubing for high pressure service, equipped with stainless steel overbraid plus tube adapter end connections, is commonly available with a carbon black-loaded PTFE core tube to dissipate static. Numerous other designs of conductive and antistatic tubing are available for low pressure applications. The utility of conductive tubing in preventing fires during transfer of aromatic hydrocarbon liquids is described in [165]. 

FIGURE 19.5 Reconstructed three-dimensional-transmission electron microscopic (3D-TEM) images of carbon-black-loaded natural mbber (NR) in black and white (upper) and in multicolored (lower) displays, (a) and (d) CB-10 (b) and (e) CB-40 (c) and (f) CB-80. The white bar of each direction shows the distance of 100 nm. (From Kohjiya, S., Kato, A., Suda, T., Shimanuki, J., and Ikeda, Y., Polymer, 47, 3298, 2006. With permission.)... 

As physical properties of the carbon-black-loaded vulcanizates, their volume resistivity (/>v) were measured and plotted in Figure 19.6. Interestingly, the behavior is very similar with that of dp. 

FIGURE 33.12 Effect of carbon black loading on abrasion resistance. 

Figure 6. Magic angle spinning, high-power proton decoupling, FT C-13 NMR spectrum of cured, carbon-black-loaded polyisoprene at ambient temperature, FT of normal FID without proton enhancement.

Payne A. R. (1962). The Dynamic Properties of Carbon Black-Loaded Natural Rubber Vulcanizates. Part I, J. Appl. Polym. Sci. 6 (19), pp 57-53. "http //en.wikipedia.org/wiki/Payne effect"... 

The ease with which a compound can be calendered is largely governed by the carbon black loading in the rubber compound and the rubber content and scorch time. Examples of two typical topping compounds are given below. 

Bright field—Mainly used to examine thin sections of carbon black loaded samples, e.g., carbon black dispersion in thin films of rubber compounds. 

Figure 9.10 The change in peak intensities at 51 ppm (A) and 45 ppm (B) for four formulations with different carbon black loading as a function of cure...

The presence of free radicals deriving from carbon black could also complicate the interpretation of NMR data in the case of filled rubbers, because radicals may cause a substantial decrease in T2. Two types of radicals have been detected in carbon-black-filled rubbers localised spins attributable to the carbon black and mobile spins deriving from rubbery chains [86]. Mobile spins are formed because of the mechanical breakdown of polymer chains when a rubber is mixed with carbon black. The concentration of mobile spins increases linearly with carbon black loading [79, 87]. 

As argued above, aggregates are efficiently diminished in size and partly broken due to the higher shear forces with increasing carbon black loading. This is emphasized in Fig. 24 by the increasing value of the mean solid frac-... 

Carbon black loading can play an important part in obtaining quality dispersion with higher loadings producing superior dispersion, other factors being equal. However, caution should be used to ensure that the concentrate viscosity does not greatly exceed that of the compound polymer—a 3 1 concentrate-to-compound... 

Molded parts prepared at 3% carbon black loading are also shown in Figure 11.5. The relationship between low- (open triangles) and high- (solid triangles) intensity mixing schemes is similar to that for 1% loaded parts. As one would expect, the 3% black loaded parts are darker. 

Figure 11.7. Outdoor weather testing, Phoenix, AZ 75-g.m sample thickness, 1% carbon black loading in LLDPE.

Figure 11-8. Tensile elongation in a carbon arc weatherometen impact of carbon black dispersion 2.5% carbon black loading in LLDPE.

In plastics, relative viscosity can be defined as the ratio of the viscosity of a concentrate to that of the neat carrier polymer at the same temperature. In this use, relative viscosity predicts relative jetness—defined in the same manner—more accurately than the carbon black loading in a concentrate. A mismatch between masterbatch and letdown viscosities causes incomplete mixing and is the reason that relative jetness can decrease with an increase in relative viscosity [5]. 

Equation (70) predicts a power law behavior G cp3-5 for the elastic modulus. Thereby, the exponent (3 + d ) / (3 - df) 3.5 reflects the characteristic structure of the fractal heterogeneity of the filler network, i.e., the CCA-clusters. The predicted power law behavior at higher filler concentrations is confirmed by the experimental results shown in Fig. 15, where the small strain storage modulus of a variety of carbon black filled rubbers is plotted against carbon black loading in a double logarithmic manner. It also agrees with older experimental data obtained by Payne [1] as shown in [63,64]. 

Fabrication of conducting plastics, mostly blends in which the conducting polymer is associated with another polymer that has higher mechanical properties, is probably the most developed application to day. Such polymeric blends appear to be much better solutions than carbon black-loaded... 

Fig. 8.19 Temperature dependence of the conductivity of carbon-black/ epoxy composites at different carbon-black loadings. Reprinted from El-Tantawy et al. (2002). Copyright 2002, with permission from Elsevier.

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