Electrical properties of PPS

Electrical properties of PPS compounds are summarized in Table II. The dielectric constant of 3.1 is low in comparison with other plastics. Similarly the dissipation factor is low. Dielectric strength is quite high ranging from 500 to 600 V/mil for the various compounds. Thus, both filled and unfilled PPS materials are excellent electrical insulators. 

The electrical properties of PPS and the ability to injection-mold very small parts with great precision have led to the use of a variety of connectors, coil forms, etc. in the electronics industry. For example, a pin cushion corrector coil used in color television sets is now being produced... 

There were conflicting reports on the effect of compatibilizer on the electrical properties of PP nanocomposites [16,47]. Lee et al. [16] reported that the electrical conductivity of PP/MWCNTs nanocomposite increased by the addition of PP-g-MA. They considered that PP-g-MA improved the interfacial adhesion between PP and nanotubes, and generated additional electrical pathway. However, their later work [47] showed that the electrical conductivity of PP/MWCNTs nanocomposite decreased when PP-g-MA was added, and the conductivity remained almost constant irrespective of the PP-g-MA content. Moreover, the percolation threshold of PP/MWCNT nanocomposites (between 0.5 and 2wt%) was shifted toward a higher value (between 1 and 2 wt%) when PP-g-MA was added [47]. 

MWCNTs are more effective than carbon black in improving the electrical properties of PP [47]. The addition of 5wt% of carbon black hardly improved the electrical properties of PP whereas 2 wt% of MWCNTs increased the conductivity by 5-6 orders of magnitude. Moreover, the percolation threshold of carbon black was much higher (10-20 wt%) as compared to CNTs [48]. 

PP-grafted CNTs are better than pristine CNTs in improving the electrical properties of PP. The incorporation of 3 wt% of MWCNTs reduced the volume resistivity of PP from 10 to 10 Q cm [49]. However, the volume resistivity of a nanocomposite containing 3 wt% of PP-grafted MWCNTs was 10 Q cm [49]. 

PP is an excellent electrical insulator, as can be expected from a non-polar hydrocarbon. The electrical properties of PP are very similar to those of PE and are compared in Table 19. 

R. E. Schawmm, A. E. Clark, and R. P. Reed,M Compilation and Evaluation of Mechanical, Thermal and Electrical Properties of Selected Polymers, NBS Report, A EC SAN-70-113, SANL 807 Task 7, SANL Task 6, National Technical Information Service, U.S. Dept, of Commerce, Springfield, Va., Sept. 1973, pp. 335-443. 

R. Bartnikas, "Engineering Dielectrics Vol. II A—Electrical Properties of SoHd Insulating Materials Molecular Stmcture and Electrical Behavior," ASTM Special Technical Publication 783, 1983, Chapts. 1—5, pp. 3—515. 

Highly desirable properties of PPS include excellent chemical resistance, high temperature thermal stabiUty, inherent flame resistance, good inherent electrical insulating properties, and good mechanical properties. 

BiaxiaHy orieated PPS film is transpareat and nearly colorless. It has low permeability to water vapor, carbon dioxide, and oxygen. PPS film has a low coefficient of hygroscopic expansion and a low dissipation factor, making it a candidate material for information storage devices and for thin-film capacitors. Chemical and thermal stability of PPS film derives from inherent resia properties. PPS films exposed to tolueae or chloroform for 8 weeks retaia 75% of theh original streagth. The UL temperature iadex rating of PPS film is 160°C for mechanical appHcatioas and 180°C for electrical appHcations. Table 9 summarizes the properties of PPS film. 

Bauer, F. (1984), Piezoelectric and Electric Properties of PVF2 Polymers Under Shock Wave Action Application to Shock Transducers, in Shock Waves in Condensed Matter—1983 (edited by J.R. Asay, R.A. Graham, and G.K. Straub), Elsevier Science, New York, pp. 225-228. 

Anderson, W. G., 1986b, Wettability Literature Search — Part 3 The Effects of Wettability on the Electrical Properties of Porous Media Journal of Petroleum Technology, December, pp. 1371-1378. 

Wilkening, M. (1987) Effect of radon on some electrical properties of indoor air. In Radon and its Decay Products, ed. P.K. Hopke, Washington D.C., American Chemical Society, pp. 377-97. 

Mineral physics studies. 10. Electrical properties of mineral aggregates. I. Natural and artificial aggregates of crystallized lead sulphide. Ibid., 3268, pp. 21-50. 

Shirakawa H, Luois EJ, MacDiarmid AG, Chiang CK and Heeger AJ, J Chem Soc Chem Comm (1977) 579. Strella S (1970, 1971), quoted by Seanor DA, in Frisch KC and Patsis A (Eds) "Electric Properties of Polymers , Technonomic Publishers Co Westport, CO, pp 37-51,1972 Chap. 3. 

Markin VS (2004) Electric properties of oil/water interfaces. In Pet-sevDN (ed) Emulsions structure stability and interactions. Elsevier, Amsterdam, pp 91-182... 

Chemical resistance and electrical properties of PMP are similar to those of the other polyolefins, except that it retains these properties at higher temperatures than do either PE or PP. In this respect PMP tends to compare well with PTFE up to 150C (300F). Molded parts made of this plastic are hard and shiny, yet their impact strength is high at temperatures down to -29C (-20F). Their specific gravity of 0.83 is the lowest of many commercial solid plastics. 

These versatile plastics are available in many grades as well as copolymers like ethylene propylene. NEAT PP has a low density of 0.90, which, combined with its good balance of moderate cost, strength, and stiffness as well as excellent fatigue, chemical resistance, and thermal and electrical properties, makes PP extremely attractive for many indoor and outdoor applications. There are hundreds of formulations that are produced. 

Bender M., Seelig W., Daube C., Ocker B. and Stollenwerk J., Dependence of oxygen flow on optical and electrical properties of DC magnetron sputtered ITO films. Thin Solid Films 326 (1998) pp.72-77. 

Edelberg, R. Electrical properties of skin. In Biophysical Properties of Skin. Harry Elden, ed. New York, Wiley-Interscience, 1971, pp. 513-549. 

Borodin, M. Ya. Electrical properties of plastic foams. In Plastic foams. Popov, V. A. (ed.), pp. 61-72. Moscow Oborongiz 1959 (In Russian)... 

Domkin, V, S. Electrical properties of plastic foams and methods of estimation. In Methods of physico-mechanical testing of plastic foams, pp. 48-53. Moscow NIITEKhIM 1976, (in Russian)... 

In the last years we devoted considerable effort to understand the properties of pp chromophores in different environments. The basic idea is that pp chromophores respond largely and non-linearly to electric fields, being them externally applied field, or internal fields generated by the interaction with the surrounding. In this section we will briefly review our work on NLO responses of pp chromophores and on their spectroscopic behavior in solution. This work set the stage for building up models for mm based on pp chromophores, where intermolecular electrostatic interactions dominate the physics of the material. 

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