Poly(ether imide) is a polymer that has very good mechanical and thermal properties and is used, among other things, to produce the internal parts of aircraft. However, like most polymers it is an insulating material from the electrical perspective.

Carbon nanotubes have excellent mechanical properties, are very tough, very rigid, and they conduct electricity; however, “The problem with them is that they get dispersed, in other words, it’s very difficult to get them to blend with polymers,” explained Iñaki Eguiazábal, a member of the Polymer Technology Group.

The PTG research, reported in the journal Composites, Part A: Applied Science and Manufacturing, developed a method for the successful preparation of such a composite.

Ternary systems based on polymer blends to which nanoparticles have been added have enabled the advantages offered by the blend to be combined with those provided by nanocomposites; this includes the obtaining of super-tough materials with an optimized range of properties.

By adding carbon nanotubes, we are not only able to improve the mechanical properties of the material even further, we can also turn it into a conductor of electricity. thermal stability is reduced, electrical conductivity is obtained by adding 1% of carbon nanotubes. Finally, to all this is added the fact that the viscosity of the nanocomposites is seen to be significantly reduced thanks to the presence of the poly(butylene terephthalate), which constitutes a considerable improvement in the processability of the materials, despite the presence of the nanotubes that tend to increase viscosity. This reduction in viscosity makes it possible to obtain products with sections of very little thickness but with complex geometry.

—Iñaki Eguiazábal

Resources

• I. González, J.I. Eguiazábal (2013) “Widely dispersed PEI-based nanocomposites with multi-wall carbon nanotubes by blending with a masterbatch,” Composites Part A: Applied Science and Manufacturing, Volume 53, Pages 176-181, doi: 10.1016/j.compositesa.2013.06.011