Page 205 - Engineering Plastics Handbook

178 Engineering Plastics

■ Lighting reflectors: heat resistant, excellent dimensional stability,
smooth surface as molded, good metal adhesion without secondary
operations, and light weight [52]
■ Medical: autoclave and gamma radiation resistance to allow repeated
sterilization, transparent, and break-resistant [54]
■ Fluid handling: excellent dimensional stability, transparent, solvent-
and hydrolysis-resistant, with high burst strength
■ Electrical: high continuous-use temperature, nonhalogenated inher-
ent ignition resistance, good dielectric properties, dimensionally
stable, and very low levels of ionic species
■ Automotive underhood: excellent dimensional stability, light weight,
high strength and stiffness, resistance to hot solvents, complex part-
design freedom, and parts consolidation
■ Wire coating: high continuous-use temperature, flexibility (i.e., silicone
PEI copolymer), ignition resistance, low smoke, and low smoke cor-
rosivity

Summary

Thermoplastic PEI resins offer high performance with the benefits of melt
processing. Chemical structures that provide two or more flexible linkages
may result in polymers that are melt-processable. Proper choice of these
flexible linkages can allow retention of both short-term and long-term
heat resistance. Thermoplastic polyetherimides have high strength and
dimensional stability as well as inherent ignition resistance, good electri-
cal properties, transparency, and practical impact strength. PEI resins are
easily metallized and recycled. They meet a variety of requirements for the
molding and processing community as well as the demanding needs of
many end-use applications. New members of this resin family are con-
stantly under development.

References

1. Verbicky, J. W., “Polyimides,” Encyclopedia of Polymer Science and Engineering,
vol. 12, Wiley, New York, N.Y., USA, 1988, pp. 364–383.
2. Takekoshi, T., “Polyimides,” Advances in Polym. Sci., 94:1–25, 1990.
3. Takekoshi, T., “Synthesis of Polyimides,” Plastics Engineering, 36:7–48, 1996.
4. Preston, J., “Polyimides,” Supplemental Volume, Kirk-Othmer Encyclopedia of
Chemical Technology, Wiley, New York, N.Y., USA, 1971, pp. 746–773.
5. Ghosh, M. K., and Mittal, K. L., eds., Polyimides Fundamentals and Applications,
Marcel Dekker, New York, N.Y., USA, 1996.
6. Sroog, C. E., “Polyimides,” Progress in Polym. Sci., 16(4):561–694, 1991.
7. Sroog, C. E., “Polyimides,” J. Polym. Sci.: Macromolecular. Rev., 11:161–208, 1976.
8. Sroog, C. E., Endrey, A. L., Abramo, S. V., Berr, C. E., Edwards, W. M., and Oliver, K.
L., “Aromatic Polypyromellitimides from Aromatic Polyamic Acids,” J. Polym. Sci.,
Part A: Polym. Chem., 34(11):2063–2086, 1996.