Nanocomposites are the next Big Thing
According to a 2004 report from Business Communications Company (Norwalk, CT), the total worldwide market for polymer nanocomposites reached 11,100 tonnes, valued at $90.8 million in 2003, while growth of 18.4% per annum forecast through to 2008 would more than double the size of the market in five years.
Confronted with issues such as high cost, longer product development cycles, and potential safety issues, it''s still uncertain as to how fast the nanocomposites market will actually expand. But judging from the amount of work going on globally at numerous firms, the materials look set to play a key role in the future of plastics processing.
Carl Hagstrom, COO of Hybrid Plastics in Hattiesburg, MS, says forecasts tend to be too optimistic in the short term, but underestimate long-term prospects. He notes that a lot of work is going on behind the scenes. "Companies don''t want to advertise the fact [that they''re working with nanocomposites] as they want to gain a competitive advantage."
A lot of Hybrid Plastics'' customers apparently fall into that category. The firm was spun off from the Air Force Research Laboratory to commercialize polyhedral oligomeric silsesquioxane (POSS), a molecule possessing an inorganic silicon and oxygen cage structure with an organic carbon group on each corner. Addition of these "nanostructured chemicals" imparts performance improvements such as flame retardance, barrier properties, impact strength, and toughness, among others. "Nanoadditives are not a drop-in replacement," cautions Hagstrom. "A lot of technical support is required to make sure things work right." In October 2004, Hybrid Plastics started supplying POSS masterbatches. Sales doubled in that year; in 2006, the firm plans to double capacity.
Firms are working to apply nanocomposites to auto applications where they would enable all-important weight saving. GE Advanced Materials (Pittsfield, MA) is in the process of commercializing stiff, but ductile, and paintable nanocomposites for body exterior components, while Dow Chemical, based in Midland, MI, has developed a reactive extrusion process to produce nanocomposites based on organoclays and cyclic butylene terephthalate (CBT) supplied by Cyclics.
In already commercial applications, GM employs polypropylene-based nanocomposites developed by Basell USA (Elkton, MD) and Southern Clay Products (Princeton, NJ) in the open cargo bed of the 2005 Hummer H2 SUT to save weight and ensure dimensional stability under harsh conditions. In all, GM uses about 300 tonnes of nanocomposites annually, spread over several vehicle models.
Further, Süd-Chemie AG (Moosburg, Germany) and Putsch Kunststoffe GmbH (Nuremberg, German), have developed ELAN XP nanocomposite grades based on PP/PS blends for automotive interiors. PP and PS are not normally compatible but Süd-Chemie''s Nanofil mineral filler produces compounds with high scratch resistance, a uniformly matte surface, and pleasant tactile properties.
"ELAN XP behaves basically like PP with the shrinkage of ABS or mineral-filled PP," says CEO Peter Putsch. Compounds are supplied precolored, whereas