Polymer blend carbonization

Table 3 Yields of HKL/synthetic polymer blend carbon fibers in each step of carbon fiber production...

Brigandi PJ, Cogen JM, Pearson RA (2014) Electrically conductive multiphase polymer blend carbon-based composites. Polym Eng Sci 54 1... 

It is known that carbon-black filled polymers conduct electric current only with the concentration of carbon black exceeding the threshold of percolation ((p ). In heterogeneous polymer blends carbon black is distributed nonuniformly between polymer phases. If the concentrations of carbon black in both phases of a blend are lower than (p, the blend can conduct electric current only subject to the condition that the part of carbon black is localized at the interface and its concentration here reaches the percolation threshold [12]. So if the concentration of carbon black in both phases of a blend is only slightly lower than (p, even a minor accumulation of carbon black at the interface confers conductivity on the polymer blend. This enables the extent of carbon black aggregation at the interface to be judged by the conductivity value. 

The polymer blend carbonization method will become an important tool for producing carbon membranes, with mixed-matrix materials, to overcome the challenges and limitations of membrane technology used in the gas separation industry. 

Ozaki J, Endo N, Ohizumi W, Igarashi K, Nakahara M, Ohya A, Yoshida S, lizuka T (1997) Novel preparation method for the production of mesoporous carbon fibre from a polymer blend. Carbon 35 (7) 1031-1033... 

Suarez-Garcia, F., Vilaplana-Ortego, E., Kunowsky, M., Kimura, M., Oya, A., Linares-Solano, A., 2009. Activation of polymer blend carbon nanofihres by alkaline hydroxides and their hydrogen storage performances. International Journal of Hydrogen Energy 34 (22),... 

A polymer blend is a physical or mechanical blend (alloy) of two or more homopolymers or copolymers. Although a polymer blend is not a copolymer according to the above definition, it is mentioned here because of its commercial importance and the frequency with which blends are compared with chemically bonded copolymers. Another technologically significant material relative to the copolymer is the composite, a physical or mechanical combination of a polymer with some unlike material, eg, reinforcing materials such as carbon black, graphite fiber, and glass (see Composite materials). 

The important yet unexpected result is that in NR-s-SBR (solution) blends, carbon black preferably locates in the interphase, especially when the rubber-filler interaction is similar for both polymers. In this case, the carbon black volume fraction is 0.6 for the interphase, 0.24 for s-SBR phase, and only 0.09 in the NR phase. The higher amount in SBR phase could be due to the presence of aromatic structure both in the black and the rubber. Further, carbon black is less compatible with NR-cE-1,4 BR blend than NR-s-SBR blend because of the crystallization tendency of the former blend. There is a preferential partition of carbon black in favor of cis-1,4 BR, a significant lower partition coefficient compared to NR-s-SBR. Further, it was observed that the partition coefficient decreases with increased filler loading. In the EPDM-BR blend, the partition coefficient is as large as 3 in favor of BR. 

See also Carbon monoxide (CO) Cocondensation resins, 15 778-780 Cocontinuous morphology, in polymer blends, 20 329-330... 

Morpholine chromate, molecular formula, properties, and uses, 6 562t Morphology. See also Structure of carbon fibers, 26 737-739 of high density polyethylene, 20 162 of polymer blends, 20 356 of polymer colloid, 20 386-388 of PVC particles, 25 658-661, 661-663, 664-665... 

The electrical conductivity of two-phase, incompatible polymer blends containing carbon black has been shown to depend on the relative affinity of the conductive particles to each of the polymer components in the blend, the concentration of carbon black in the filler-rich phase, and the structural continuity of this phase [82]. Hence, by judicious manipulation of the phase microstructure, these three-phase filled composites can exhibit double percolation behaviour. 

Coalescence is another reverse process in mixing. Whereas this is a major issue in the formation of polymer blends, it is considered of less significance with carbon black or other solid filler dispersions in polymers [83]. 

This review encompasses the chemistry that is involved in the synthesis, characterization, degradation and the derivatization of the copolymers of carbon monoxide with olefins. In addition, work on the spectral characterization of the copolymers has been cited. Discussions of the physical properties of the copolymers, as well as, their practical applications (for example, as a component in polymer blends), are outside its purview. The review is based on reports published in journals and United States patents up to 1984. 

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