quote:

Chemical & Engineering News July 18, 2011 Volume 89, Number 29 pp. 29 - 31 Preserving Plastic Art Chemistry of polymer-based creations presents unique problems for conservators Sarah Everts Since the invention of plastics in the late 1800s, artists and designers have been using them to make everything from high-fashion hair combs and intricate sculptures to moon-mission spacesuits. But “the number of plastics used by artists increased dramatically in the 1960s,” Shashoua explains, during that era’s love affair with all things plastic and the corresponding increased availability of polymers. Yet it took until the 1990s before the museum world got over what conservators refer to as “plastics denial syndrome”—denying that plastics in a museum’s collection have short lifetimes and degrade—and woke up to the fact that many pieces of plastic-containing art were in grave danger of being lost, van Oosten says. ... Although cellulose acetate, cellulose nitrate, PVC, and polyurethane are the most problematic plastics, museum objects made from polyester and polypropylene are also beginning to show problems, Shashoua says. Because any conservation or cleaning strategy is specific to a plastic type, museum staff need to know an object’s precise plastic makeup. But few plastic art objects come with a chemical ingredient list, and not all museums have laboratories with the tools—primarily infrared and other spectroscopic equipment—to help analyze them. Conservators sometimes have to rely on their sense of smell to guide their plastic diagnosis, Shashoua says. Leaching phthalate plasticizers give PVC the smell of a new car, she explains, while cellulose acetate smells like vinegar, and polyester has the odor of raspberry jam, cinnamon, and burning rubber.