Alas, the production of lightweight and durable carbon fiber is still costing a pretty penny. Scientists at the University of Johannesburg (South Africa), led by Professor Tian-Chen Jen, are proposing a cheaper and more reliable alternative - a new material in which carbon fibers are replaced by fibers extracted from banana trees.
To separate these fibers, a special soaking method in water is used, after which they are placed for four hours in a 3% caustic soda solution, dried, treated for two minutes with high-frequency microwave radiation, and then dispersed (crushed) in ethanol to prevent thickening.
As a result, the treated fibers bond better with epoxy resin containing a small amount of carbon nanotubes. The best quality is a mixture of one part banana fibers and four parts resin with nanotubes, which account for only 1% of the weight. The resulting mixture is loaded into a mold and put under a press for 24 hours.
According to the results of mechanical laboratory tests, it turned out that the resulting composite material is stiffer and stronger than "pure" resin - by 31% in tension and 34% in bending. Plus, the new material has a higher impact resistance and thermal conductivity.
The scientists hope that the banana-based composite they have created will eventually find use in the manufacture of lightweight, durable automotive parts.