Nanotube-based composites promise exciting future

Nanocomposites are one of the most exciting areas in the plastics industry.
According to the Exton, Pa.-based Principia Partners, nanocomposites both of the nanoclay or nanocarbon filler type are expected to become a major growth segment for the plastics processing industry. The use of nanocomposites has shown steady growth in such markets as automotive, packaging and electronics. It is expected by 2008, the polymer nanocomposite market in the United States could grow to US$250 million from US$75 million in 2004.
Right now, the most common kinds of nanocomposites use layered silicate nanoclays, nanotalcs and graphite platelets. Nanoclay composites appearing in a wide range of commercial thermoplastics. In the automotive market, for example, nanocomposites have been used in such vehicles as General Motors’ 2004 Chevrolet Impala and the Hummer H2 used a TPO nanoclay formulation in some of its parts.
But Pascal Hubert, Canada Research Chair in Advanced Composite Materials with Montreal-based McGill University said the most interesting developments in nanocomposites for the plastics industry will come from the research being done on nanotube polymer nanocomposites. Hubert’s work is around developing and analyzing new composite materials and process modeling technologies, especially around carbon-based nanotube polymer nanocomposites.
Hubert said nanotube polymer nanocomposites offer a variety of interesting features appealing to plastics processors. Nanotube-based nanocomposites offer the possibility of manufacturing plastic parts that have very high strength, stiffness and low density of the reinforcement, he said.
This means in the aerospace industry, for example, these kinds of nanocomposites could be used to build aircraft parts that are lighter and stronger than today’s metal or plastic parts. Having lighter parts means an aircraft would use less fuel when operating; and increased strength means that aircraft could be built even larger than before without sacrificing safety. The same goes as well for the automotive industry as automobiles could be build lighter using these nanotube polymer nanocomposites, thereby saving in fuel costs but without sacrificing safety.
“But while all of this looks very good in theory, there are still a lot of practical problems that have to be overcome,” Hubert added.
The first hurdle to overcome is in the manufacturing of the nanotubes. Hubert’s research is focused on trying to develop techniques that will produce nanotubes in sufficient quantities to be commercially viable while maintaining a high degree of quality and consistency in tube size and diameter. As well, there are problem in how the nanotubes and polymers are combined. Nanotubes have a tendency to clump up or bunch together, making it difficult to have the nanotubes distributed uniformly throughout the polymer.
“Right now, there are also a lot of questions as to whether the technologies we are using in the manufacture of regular composites is the right way to go in the manufacture of nanocomposites with these nanotubes,” Hubert said.
Marifaith Hackett, senior consultant for the Menlo Park, Calif.-based SRI Consulting Business Intelligence (SRIC-BI) believes work is well underway in many quarters to overcome these problems and making such nanocomposites more commercially attractive in the long-run.
“I see the price of carbon nanotubes dropping, and supply increasing, which is going to encourage more use of such materials, Hackett added. “In the short-terms they are going to be expensive materials and there will be a lot of experimentation with them at first.”
Still, Hubert believes once these questions are tackled, nanotube-based polymer nanocomposites will become very important to the plastics industry as they open up new design and manufacturing opportunities.