Washington, June 29 (ANI): Mesoamericans were the first polymer scientists - they made rubber from latex nearly 3,500 years long before modern vulcanisation was invented.
According to a new research, by a team at the Massachusetts Institute of Technology (MIT), pre-Hispanic peoples not only invented rubber, but also perfected techniques of chemical processing to enhance its properties.
They manufactured strong, wear-resistant rubber.
Flourishing from about 2,000 B.C. to the Spanish invasion in 1521 in what are now parts of Mexico and Central America, the Mesoamerican civilization engineered the properties of latex from the native Castilla elastica tree.
A milky sap-like fluid that dries to a brittle solid, natural latex, which contains an oily chemical called isoprene, was blended with juice from the morning glory species Ipomoea alba.
The Mesoamerican people stirred the liquid till the time it solidified into a white mass that was moulded by hand into rubber balls, hollow rubber figurines, and other rubber artefacts.
The process relies on chemistry, bearing resemblance to modern vulcanisation.
For the new research, archaeology professor Dorothy Hosler and technical instructor Michael Tarkanian of MIT's Department of Materials Science and Engineering, set up their own processing facility at MIT, and experimented using raw materials collected during field trips to Mexico.
They found that by varying the proportions in the mixture made of Castilla tree sap and morning-glory vine juice, a different kind of rubber could be made.
A 50-50 blend of the latex and morning glory produced maximum bounciness, perfect for the rubber balls.
Pure latex worked best for rubber bands and adhesives, while a three-to-one mix of latex to morning glory provided the most durable material, perfect for sandals.
The Mesoamericans had plenty of time to work out these properties through trial and error.
By the time the Spanish arrived, there was "a large rubber industry in the region, producing 16,000 rubber balls each year, and large numbers of rubber statues, sandals, bands and other products," Discovery News quoted Tarkanian, as saying in a MIT statement.
A few such balls, which ranged in size from a few inches to a foot across, have been found in archaeological digs in the region, with oldest dating back to 1600 B.C.
These balls were used in ceremonial ball games. (ANI)