Polymers graphite-filled

Carbon C (electrographite, Acheson graphite) Carbon black-filled polymers, graphite-filled plastics, graphite-felt, glassy carbon (anode only), porous carbon, poly-p-phenylene (synthetic metal)... 

Garbon- or graphite-filled polymers or a carbon paste, which can easily be regenerated by removing a surface layer, are also possible electrode materials. 

The electrolyte is a perfluorosulfonic acid ionomer, commercially available under the trade name of Nafion . It is in the form of a membrane about 0.17 mm (0.007 in) thick, and the electrodes are bonded directly onto the surface. The electrodes contain very finely divided platinum or platinum alloys supported on carbon powder or fibers. The bipolar plates are made of graphite-filled polymer or metal. 

Polymers may also be converted from nonconductors to conductors of electricity by the addition of conductive fillers. Graphite-filled polymers are semiconductors, and polymers filled with aluminum flakes or aluminum filaments are relatively good conductors of electricity. 

Bian, XC Tang, JH Li, ZM. et al. Dependence of flame-retardant properties on density of expandable graphite filled rigid polyurethane foam. J. Appl. Polym. Sci. 2007, 104, 3347-3355. 

Two series of graphite-filled polymers were used in the following experiments with nonactivated graphite (I) and with graphite activated by the mixture of sulfur and nitric... 

Ticona has co-operated with SGL Carbon to produce a graphite-filled liquid crystal polymer, also for fuel cell plates. There are likely to be 200 bipolar plates for each cell, and two cells per vehicle. The filled polymer is meant to be injection moulded, but this requires much higher throughputs than compression moulding to be economic. 

Perhaps the largest volume commercial production of particle-filled polymers is carbon- or graphite-filled rubbers. Carbon blacks are widely used in natural and synthetic rubbers and convey significant improvements in modulus, abrasion resistance, and tear strength as well as additional thermal and electrical conductivity. Carbon blacks are uniquely efficient in these respects the reasons for this are still the subject of debate. A very recent review by Rigbi is an excellent compilation of current theory and experiment. An earlier review by Medalia ... 

G. Wu, J. Lin, Q. Zheng, and M. Zhang, Correlation between percolation behavior of electricity and viscoelasticity for graphite filled high density polyethylene. Polymer, 47 (2006), 2442-7. 

A process that is certainly cheap is the injection moulding of graphite filled polymer... 

Low-end silver epoxies Graphite-filled coatings Polyamide Oxide-filled epoxies Unfilled epoxies Dielectric polymers Poly(tetrafluoroethylene)... 

Figure 7.38 Lubricated friction test dynamic coefficient of friction versus ZN/P by thrust bearing test against steel with Sunvis 31 oil lubricant of DuPont Engineering Polymers Vespel SP-21—15% graphite-filled PI [9], ZN/P is the nondimensional parameter controlling lubricant film thickness. Z, lubricant dynamic viscosity N, revolutions P, contact surface pressure.

Figure 7.42 Pressure versus velocity limit at 395°C against unlubricated carbon steel of DuPont Engineering Polymers Vespel SP-21—15% graphite-filled PI [9].

Filled Resins. EiEers such as glass fibers, graphite, asbestos, or powered metals are compounded into all three types of PTEE. Compounding is achieved by intimate mixing. Coagulation of the polymer with a filler produces a filled fine powder. 

These consist of a number of parallel slots cut into the concrete surface. Each slot is then filled with a secondary anode of carbon/graphite fibres embedded in a conductive polymer grout. The current to each of these secondary anode systems is provided by a primary anode of platinised niobium wire placed in slots filled with conductive polymer which acts as the primary anode, these slots intersecting each slot of graphite fibre/conductive polymer at right angles. 

Fig. 2. Relationship of conductivity of polypropylene-based polymer composites and filler concentration (natural graphite) 1 — polymerization filling 2 — mechanical mixture [24]...

Natural graphite and synthetic graphite were used as fillers for the manufacture of conducting composite materials by the polymerization filling technique [24, 53-56], The manufacture of conducting polymer composite materials by this technique on the basis of some kinds of carbon black is also known [51, 52],... 

Alternative explanations of the high conductivity of composite materials obtained by polymerization filling are given in works [62, 63] where conductivity higher than that of the graphite proper is attributed to a polymer interlayer between graphite particles, are, in our opinion, insufficiently convincing and cannot explain the whole of the experimental data. 

---