The National Science Foundation has awarded a $360,000 three-year grant for preservation research to the University of Southern Mississippi, Hybrid Plastics, and the National Center for Preservation Technology and Training (NCPTT). The research team is developing new stone strengtheners, also called consolidants, based on the latest advances in polymer science.
“This National Science Foundation grant creates opportunities for NCPTT to leverage its scientific expertise and resources by funding a partnership with university and private-sector researchers,” Kirk Cordell, NCPTT executive director said “This collaboration allows us to address fundamental challenges in stone conservation to advance the field of conservation and heritage science.”
When Mary Striegel, NCPTT’s chief of materials conservation, wanted to find new partners to develop innovative treatments for deteriorating historic stone monuments and structures, she turned to scientists in Hattiesburg, Miss. Joe Lichtenhan and his team at Hybrid Plastics were pioneering the use of a new group of polymers based on modifying POSS (Polyhedral Oligomeric Silsesquioxane) molecules. Meanwhile, Derek Patton, an assistant professor at the University of Southern Mississippi, was studying interactions of polymers and surfaces and has an interest in new ways to synthesize polymers. Striegel thought that POSS molecules could be applied to preservation problems.
Decay leads to loss of stone strength. The outer surface of the stone can powder away, or can fall off in pieces. Consolidants are chemicals that are applied to and strengthen the surface of stone. Commercially-available consolidants are on the market, but ever increasing restrictions on environmental regulations make it harder to use these products in an outdoor environment. Additionally, some of the products work better on materials like sandstone than on limestone or marble.
Proposed new stone consolidants are based on the POSS molecule’s ability to form a cage-like structure that provides strength and stability under a variety of environmental conditions. The polymers have properties that are similar to both ceramics and plastics. Depending on the modifications made to the molecules, the polymers can be used as adhesives, water repellents, or consolidants. This National Science Foundation grant will help the team design new polymers that can be applied directly to stone and cured using ultraviolet light.
The joint research effort is being conducted in laboratories in Hattiesburg, Miss. and in Natchitoches, La. As an added benefit, this unique, cross-cutting academic/industry/government collaboration is providing undergraduate and graduate students the opportunity to learn more about cultural heritage while strengthening their scientific skills.