Da Vinci Invented
Natural Plastics

By Rossella Lorenzi
Discovery News

Leonardo da Vinci not only anticipated the airplane, the life jacket, the intercom and the robot, he also created the first natural plastic, according to an Italian scholar.
Alessandro Vezzosi, director of the Museo Ideale in the Tuscan town of Vinci, where the artist was born the illegitimate child of a Florentine notary and a peasant girl in 1452, found Leonardo's recipe for artificial materials in several pages of drawings and notes.
Written in Da Vinci's characteristic "mirror-image" handwriting, running from right to left, the notes had been found in the Arundel Codex (housed in the British Library in London), Forster Codex (in London at the Victoria and Albert Museum) and the Atlantic Codex (kept in the Biblioteca Ambrosiana in Milan, Italy) and in manuscripts in France.
"He talks of a mixture. He combined colors with animal or vegetable glues, sometimes adding organic fibers," Vezzosi told Discovery News.
The Renaissance master obtained effects similar to plastic and unbreakable glass by "clothing with colors" the leaves of cabbage, lettuce, paper and even ox tripe.
The materials he coated ranged from "the back of the stomach of a heifer or a ox," "the leaves of wrinkle lettuce," "papers and little canes used as goose pens" and a "large Milanese wrinkled leaf of cabbage, which should be collected in December or January."
Following Leonardo's instructions, Vezzosi applied colors mixed with vegetable or animal glues. He then painted with many layers the materials described by Leonardo. As the first material dried, he removed it and obtained a material similar to bakelite, an early plastic that made a splash in the early 1900s.
"You have to be patient and wait until each layer of color dries completely. We used pigments similar to those applied by Leonardo. They ranged from traditional oil paint to any kind of organic materials," Vezzosi said.
The successful reproduction of Leonardo's natural polychrome plastic proved that the Florentine genius created the first man-made plastic long before Alexander Parkes invented parkesine (an organic material derived from cellulose) in 1862 and Leo Hendrik Baekeland's bakelite in 1909.
"Leonardo created a material somewhere between natural and chemical plastic. Indeed, he had already synthesized a chemical very similar to acetone. But in his experiments he always used non-toxic, organic substances," Vezzosi said.
Leonardo's polychrome mixtures were so similar to phenolic resin that they could be used to create knife handles, salt cellars, containers, and necklaces. Meanwhile, his monochrome mixtures could be used to create cups or vases that "once thrown on the floor don't break."
"It's interesting that Leonardo used layers ... to create unbreakable objects. In the case of oil painting, for example, linseed oil is the binding agent. This oil polymerizes slowly on contact with the air, forming a resistant, waterproof polymer similar to linoleum.
"This shows once again Leonardo's great innovative input - although obviously it doesn't add anything to our knowledge nowadays," Alessandro Bagno, professor at Padova University's department of organic chemistry, told Discovery News.
Copyright © 2004 Discovery Communications Inc.



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