Injection molding carbon-filled polymer

Electrodes in a capacitively coupled conductivity detector were made by injection molding carbon-filled polymer into a preformed PS chip. The polymer consisted of three conducting formulations 8% carbon black filled PS, 40% C fiber filled nylon-6,6, and 40% C fiber filled high-impact PS [774]. In another report, a movable contactless conductivity detector was also developed to allow the distance of the electrode to be adjustable [775],... 

The electrical conductivities of injection-molded, CNT-filled polymer blends are summarized in Table 12.4. For comparison. Table 12.4 also includes the literature value of conductivities of neat polymers used in this study. For each polymer blend, electrical conductivities are measured in two directions (i.e.. Directions I and II in Fig. 12.2) to determine whether the specimen is isotropic or not. It is found that there is large difference in conductivity between Directions I and II. For the CNT-filled PET/PVDF, PET/PP, and PET/HDPE, the conductivity in Direction I is about 4-8 times higher than that in Direction II. For the CNT-filled PET/nylon 6,6, the conductivity difference in the two directions is even larger, with Direction I having more than 22 times higher conductivity than Direction II. The anisotropy found in all the specimens is related to the partial alignment of carbon nanotubes in the... 

In spite of the substantial progress made with the concept of carbon-filled polymer blends containing a triple-continuous structure, the carbon-filled polymer blends studied so far only contain relatively low carbon concentrations. As a result, their electrical conductivities are still far below the desired values (such as >100 S cm ) for the application of PEM fuel cell bipolar plates. Therefore, it is imperative to investigate (a) whether such a triple-continuous structure can still be injection molded for polymer blends with high carbon concentrations (e.g., >30 vol% carbon) and (b) whether the polymer blends with high carbon concentrations and a triple-continuous structure, if injection moldable, still possess superior electrical conductivity and mechanical properties. Both issues will be the topics of future studies. 

BPA/DC-based composition served as a polymer matrix in carbon fiber composites [24]. Metal powder or fiber filled molding compounds were also described. The molding compounds, which can contain, moreover, numerous other components, bismaleimides (cf. Sect. 5) in particular, are used for the manufacturing of heat conductive molds for injection molding [25],... 

This polymer represents an important matrix for carbon fiber filled injection molding compounds and the molded parts have good tensile strength, impact strength and heat resistance. 

Some studies with filled and unfilled rigid PVC were made in our laboratory to describe the effect of chalk as additional stabilizer. A suspension PVC (K-value 70) with an organotin stabilizer (2 phr) and lubricants (1.8 phr) was used as the experimental material. A part of this compound was filled with a stearic acid coated calcium carbonate (10 phr) as an additional component. The PVC powder and the additives were mixed at a high speed in an intensive mixer. The received dry blends were pelletized by extrusion to get a better dispersion of the additives in the polymer material. Finally, the granulates were processed by injection molding to test specimens for measurements of mechanical properties. 

Chapter 12 deals with carbon nanotube (CNT) fiUed membranes for PCMs. CNT-filled polyethylene terephthalate was blended with various polymers, injection molded and characterized by different methods. 

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