Scientists have developed a more effective way to use fibres from bananas, pineapples and other plants to make a new generation of green vehicles.
Brazilian researchers have found the natural solution to a new generation of automotive plastics that are stronger, lighter, and more eco-friendly than plastics now in use.
With manufacturers building hybrids that have excellent gas mileage, the next step appears to be new vehicles that are created through the fruits of workers’ labours, literally – cars and planes made, in part, out of bananas or pineapples.
The study, explaining how they can create stronger, lighter, and more sustainable materials for cars and other products, was presented this spring at the ACS 241st National Meeting & Exposition in Anaheim.
Study lead author Alcides Leão, of São Paulo State University College of Agricultural Sciences, Brazil, explained: “The properties of these plastics are incredible. They are light, but very strong — 30 per cent lighter and 3-to-4 times stronger than the materials used today. We believe that a lot of car parts, including dashboards, bumpers, side panels, will be made of nano-sized fruit fibres in the future.
“For one thing, they will help reduce the weight of cars and that will improve fuel economy. They also will help us make more sturdy vehicles.”
Besides cutting down on weight and improving gas mileage, nano-cellulose reinforced plastics have mechanical advantages over conventional automotive plastics. These new plastics can reduce damage from heat and spilled gasoline, for example.
“These new polymers can replace certain plastics used today or can be used to reinforce materials and this is a real advantage because the fruit plastics are biodegradable. Any source of cellulose-related material could be used,” added Leão.
“In fact, sludge from pulp and paper cellulose plants could be used. This sludge pulp accounts for a huge amount of waste in Brazil and other countries.
“How could you use fruit to build sturdier cars, some people have asked? The fact is that the nano-cellulose fibres that go into the plastics are almost as stiff as Kevlar, the renowned super-strong material used in armour and bulletproof vests.
“Unlike Kevlar and other traditional plastics, which are made from petroleum or natural gas, nano-cellulose fibres are completely renewable. We now have a partnership with a Malaysian company to use these fibers to develop a bullet-proof vest.”
The process, though currently expensive, has a major advantage which offsets the cost, and the approach looks promising for manufacturing other products in the future. Increasing production will help reduce the cost.
“To prepare the nano-fibres, we inserted the leaves and stems of pineapples or other plants into a device similar to a pressure cooker. We then added certain chemicals to the plants and heated the mixture over several cycles, producing a fine material that resembles talcum powder.
“The process is costly, but it takes just one pound of nano-cellulose to produce 100 pounds of super-strong, lightweight plastic. So far, we’re focusing on replacing automotive plastics. But in the future, we may be able to replace steel and aluminium automotive parts using these plant-based nanocellulose materials. In addition, the new plastic could be used to build airplanes.”