Insights and curiosity
Carbon
Carbon (from the Latin carbo meaning “coal”) has a long history. We have evidence of its use already in ancient times, in fact, the primitive populations already produced it, burning organic material with little oxygen. It will be used later for the production of inks, as testified by Caio Plinio – writer and naturalist of ancient Rome – writing about the use of “carbon black” in the preparation of inks for writing and printing. Last but not the least, carbon is the fundamental element of all organic chemistry that underlies the functioning of living organisms
“Carbon, in fact, – as Primo Levi states in The Periodic System, 1975 – is a singular element: it is the only one that can bind itself in long stable chains without great energy expenditure, and to life on earth (the only one we know so far) we need long chains. Therefore carbon is the key element of the living substance”.
In nature carbon is found both in the free state and in combination with numerous compounds. It is present in nature in different forms (or allotropes) such as graphite, one of the softest materials and diamond, one of the hardest.
Carbon fiber
Carbon fiber were first used by Thomas Edison in 1879 as a glowing filament in his experiments for the production of the first bulb, later replaced with tungsten. In the fifties were then discovered composite materials, or advanced structural materials in which different components are integrated with each other to produce a material with superior characteristics from a physical, mechanical, chemical and aesthetic point of view, based on carbon fibre. Roger Bacon – physicist and naturalist of the first century – realized at the Parma Technical Center, in Ohio, in 1958, the first high-performance carbon fiber. There are mainly two types of fiber: the first called Carbon-PAN (Polyacrylonitrile) that derive from the modification of organic fibers such as, for example, rayon or acrylic, while the second called carbon PITCH are produced by the distillation of tar residues or petroleum.
However, the first commercial developments arrived only after a few decades. It is a fact that thanks to its excellent mechanical strength, lightness, thermal insulation ability, resistance to temperature changes and the effect of chemical agents, the carbon fiber composite has become the most used lightweight material, to replace conventional metal materials. Its specific gravity is about 1.5 – 1.8 g/cm3, approximately a quarter of that of iron and just over half of that of aluminum. To make carbon fibers, two elements are needed: carbon fibers, which constitute the mechanical property and a matrix, usually a resin that has the function of fixing the fibers between them.
By obtaining this compound in the form of thin filaments it proceeds with its oxidation in an inert atmosphere at very high temperatures, which can reach 2000° C. Heat triggers a series of chemical reactions, the result of which is the elimination of atoms other than carbon. Organic chains merge to create a single filament with high mechanical properties and very low weights. The result is a kind of fabric consisting of a set of thousands of carbon filaments with a thickness ranging from 5 to 10 mm. A carbon filament is composed of thousands of tubular fibers that have a diameter of 5-6 µ, consisting almost exclusively of carbon.
The dimensions of a carbon fibre and a human hair compared under the microscope.