Deterioration of PVC is manifested by its change in colour from white to yellow to pink to brown and, eventually, black. So basically older-model Barbies tend to sweat, cry and then change colour. Losing a doll may not seem like a big deal, but even Barbie is still part of western heritage. Not only that, but the PVC she's made from provides an insight into the evolving science of polymer engineering, and it was ultimately the use of plastics that caused the explosive growth of our consumer society. Rubber protection Pat Townley, Manager of Conservation at Sydney's Powerhouse Museum, says that part of the problem with protecting plastics is that their long-term behaviour has yet to be observed.
Plastics are infinitely variable, especially where they have been used in composite materials.
How they will break down is hard to predict. The worst-affected modern substances seem to be rubber compounds. Everybody knows how an elastic band can perish after a while, and the same thing is happening to the natural or synthetic rubbers employed in 20th century products. Early spacesuits made extensive use of rubber for an airtight seal, and many of the older suits are now decaying. Perversely, it's the oldest plastics of all that are proving the most durable.