Hyperbranched polymers, tree-like molecules, are not particularly useful for the creation of plastic films and molded parts because they don't entangle. So Virginia Tech researchers have created segmented hyperbranched plastics, which do entangle and result in high-performance polymers.
Virginia Tech chemistry professor Timothy E. Long of Blacksburg will describe the configuration and functionality of the new family of polymers at the 227th Annual Meeting of the American Chemical Society, being held in Anaheim, Calif., March 28 through April 1, 2004.
"We have placed extended sequences between the branch points," said Long. "Think of elastic springs. If a tree's branches were on springs, they would more easily diffuse and entangle."
These new hyperbranched polymers have excellent mechanical properties and lower viscosities, he said "One of the holy grails of polymer science is a material with excellent mechanical properties that is very easy to process. In this instance, the properties are tensile strength and rheology. These polymers have excellent stress and strain behavior and are less resistant to flow under force or temperature compared to related linear polymers."
He said that any polymer prepared as a linear molecule can be prepared easily in the segmented hyperbranched fashion. "The potential impact is tremendous. It means that we can create higher performance fuel cell materials, biocompatible elastomers, and rapid photo-curable adhesives, for example." .