Editorial Feature

Nanoparticles vs. Rubber - Could Nanomaterials Replace Rubber?

Rubber, like cotton, is an agricultural commodity sourced primarily in its natural form from southern producers such as India, Indonesia, Thailand and Malaysia. Unlike cotton, natural rubber has proven more resilient to the challenge of synthetic counterparts developed during World War II. Although 75% of world rubber was synthetic in 1964, the introduction of radial car tyres helped revive the market for natural rubber. In 2004, total global rubber production is expected to be 19.61 million tonnes of which 8.26 million will be natural rubber (42%).

Tyre Companies Who Benefit From Using Engineered Nanoparticles in their Products

Currently around 50% of a car tyre is made from natural rubber. Small particles of carbon black (including nanoparticles) have long been mixed with the rubber to improve the wear and strength of tyres. Many leading tyre manufacturers are now developing engineered nanoparticles to further extend tyre life. Cabot, one of the world’s leading tyre-rubber producers, successfully tested “PureNano” silica carbide nanoparticles designed by Nanoproducts Corporation of Colorado. Added to tyres, the “PureNano” particles reduced abrasion by almost fifty percent - a simple improvement that if widely adopted should help tyres last up to twice as long and thereby significantly reduce the need for new tyre-rubber. At present, 16.5 million tyres are retread every year in the US alone. Presumably that number would shrink by almost half. Other companies are looking to incorporate carbon nanotubes, boasting of tyres that would outlive the car entirely. According to rumours in Silicon Valley, a contraceptive manufacturer is also looking at the possibility of adding carbon nanotubes to similarly strengthen condoms.

Using Nanoclays in Tennis Balls and Car Tyres

Nano changes are scheduled inside tyres as well. Companies such as Inmat and Nanocor produce nanoparticles of clay that can be mixed with plastics and synthetic rubber to create an airtight surface. Inmat’s nanoclay has already been used as a sealant for “double core” tennis balls produced by sports manufacturer Wilson. The Double Core balls are said to have twice the bounce because the nano-particles lock in air more effectively. Inmat, which was originally set up in co-operation with Michelin, the world’s leading tyre manufacturer, believes the same technology could be used to seal the inside of tyres, reducing the amount of butyl rubber required and making tyres lighter, cheaper and cooler running.  

Could Nanomaterials Such as Aerogels End Up Replacing Rubber?

The real prize is to replace rubber altogether. One option is a super lightweight nanomaterial known as an aerogel, which was proposed as a solid tyre material for the Mars lander (in the end they went with normal tyres). As the name suggests, aerogels are largely composed of air (98%) - billions of nano-air bubbles in a silica matrix. Besides being light, aerogels are extremely heat resistant and make exceptional insulators. University of Missouri- Rolla (USA) chemists claim to have developed a new waterproof aerogel that could be used in place of tyre-rubber. At least one tyre company, Goodyear, holds a patent on a tyre that incorporates silica aerogels for its tread. The global tyre market is dominated by five multinational firms: Michelin, Bridgestone, Goodyear, Continental and Sumitomo. In 2001, the top 5 tyre manufacturers accounted for over two-thirds of global tyre sales.  

Source: ‘Down on the Farm: the Impact of Nano-Scale Technologies on Food and Agriculture’, ETC Group Report, November 2004.

For more information on this source please visit the ETC Group.

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