Research underway to commercialize the world’s toughest nano-fibre

More than 15 times stronger than steel fibres, single-walled carbon nanotubes are the toughest fibres known to scientists.

When they can figure out exactly why they’re so stiff, strong and tough, they will open up a world of new applications.

Both nanoclay- or nanocarbon-filled composites are expected to become a major growth segment for the plastics processing industry. Already it has shown steady growth in such markets as automotive, packaging and electronics, according to the Exton, Pa.-based Principia Partners. By 2008, the polymer nanocomposites market in the U.S. could grow to US$250 million from US$75 million in 2004, Principa said.

Right now, the most common kinds of nanocomposites used include layered silicate nanoclays, nanotalcs and graphite platelets.

In the automotive market, for example, nanoclay composites have been used in such vehicles as General Motors’ 2004 Chevrolet Impala, and the Hummer H2’s cargo bed was made from a nanoclay-filled thermoplastic polyolefin (PO).

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 involves developing and analyzing new composite materials and process modeling technologies, primarily with carbon-based nanotube polymer nanocomposites.

Nanotube polymer nanocomposites offer a variety of interesting properties that will allow plastics processors to manufacture plastic parts that have very high strength, stiffness and low-density of reinforcement, he said.

For example, these nanocomposites could be used to build parts for aircraft that are lighter and stronger any than metal or plastic part made today.

A lighter aircraft would consume less fuel, and the increased strength of carbon nanotube nanocomposite parts means aircraft, larger than those existing, could be built without sacrificing safety. The same scenario applies to automobiles as well.

“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 is in the manufacturing of the nanotubes. Hubert is developing techniques for mass-producing nanotubes to make them commercially viable while still maintaining a high degree of quality and consistency in tube size and diameter.

As well, combining nanotubes and polymers is still problematic: Nanotubes have a tendency to clump up or bunch together, making them difficult to distribute 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 in order to make such nanocomposites more commercially attractive in the long-run.

In January, Arkema opened a pilot plant at its Larq Research Centre in the Aquitaine Region of France. Using a patented catalysis process, the facility will manufacture carbon nanotubes in semi-industrial quantities, up to 10 tonnes per year. Arkema hopes this plant will spur the commercial development of carbon nanotubes and will meet the expected demand for such carbon nanotubes amongst converters in the thermoplastics, epoxy, elastomers and coatings markets.

“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.”