Rubber was a material unknown to Europeans before the Spanish reached Mesoamerica in the 16th century, but stretching back into prehistory the Olmec, Maya and Aztec peoples were familiar with and adept at making this useful product. New research by Dorthy Hosler and Michael Tarkanian at MIT shows how they may have gone about producing a variety of enhanced products using local materials.
     Archaeologists have found rubber balls used in ceremonial ball games in stone courts throughout Mesoamerica dating back as far as 1600 BCE. Diaries and other records also explain that rubber was used for statues, sandals, bands, and other items when the Spanish arrived, and that rubber production was a major industry with rubber items often being produced in outlying villages and sent to the centre as a tax payment. However, until recently it was not clear exactly how Mesoamericans had made and manipulated rubber to meet their needs.
     New research by Dorothy Hosler and Michael Tarkanian of MIT's Department of Materials Science and Engineering shows that rubber could be made by mixing latex from rubber trees with juice from morning glory vines, both available in the region. Their experiments show that by changing the proportions used Mesoamericans were able to make rubber with different properties. Mixing equal proportions of latex and morning glory juice produces maximum elasticity, ideal for rubber balls. Pure latex works well for joining materials such as wood or ceramics, while a three to one mix of latex to morning glory juice would have been suitable for producing durable sandals.
     However, in order to prove that Mesoamericans actually did produce rubber in this way requires chemical analysis or a contemporary account of the process. Nevertheless, John McCloy of Pacific Northwest National Laboratory remarks that "Ancient Mesoamerican peoples were the first polymer scientists, exerting substantial control over the mechanical properties of rubber for various applications." Hosler and Tarkanian's research will be published in Latin American Antiquity.

Source: MIT News (24 May 2010)