Perpetuating plastic

2007/06/15 Galarraga Aiestaran, Ana - Elhuyar Zientzia

• Materialak
• Kimika
• Ingurumena
• Museoak

Plastic dolls lose value as they deteriorate.

Most of the sculptures preserved in the museums are marble, iron and durable materials. These materials have long been used and last for centuries with little to deteriorate. Together with them, plastic works are young and have recently been incorporated into museums. And now they begin to realize the problem.

Thus, although plastic art has a brief cultural history compared to classic paintings and sculptures, there are works that are about a hundred years old and their conservation is a headache for those responsible for museums and art galleries.

From black to white

A reaction bleaches the black color of these images.

For example, PVC or polyvinyl chloride is the most widely used plastic. This film produced images of films such as Star Wars and other cult films. Although it may seem surprising to some, these small plastic figures have great value in the market. If they are in good condition, of course. However, over time they deteriorate and lose value.

The problem lies in the plasticizers that were added to prevent PVC from cracking. These plasticizers are physically attached to PVC. As the bond is relatively weak, over time it is released and the plasticizer comes to the surface of the material.

In addition, packaging is acidic and plasticizers form crystals in acid medium. Crystals are perceived at a glance and shape the old image. For example, the black helmet of the Star Wars character Darth Vader is bleached by the influence of the crystals. Therefore, the image loses value and the market price decreases.

According to experts, to avoid the degradation of valuable PVC objects, it is best to keep them in the domestic refrigerator.

Reaction chain

Researchers study how to avoid degradation.

In any case, PVC is not the only plastic that is damaged. In addition, cellulose acetate and cellulose nitrate have been widely used, even for artwork, and are now degrading.

For example, XX. At the beginning of the 20th century, the artist Naum Gabo made several sculptures of cellulose acetate and René Lalique, of cellulose nitrate. The first plastic dolls were also made of cellulose nitrate. The problem is that they degrade over time through a reaction chain that drives light.

This chain of reaction is unstoppable, but researchers are trying the way to stop. In the degradation of plastics olorizable gases are released which are nitric acid or acetic acid depending on the plastic. Gases participate in the reaction, so researchers believe that removing these gases from the environment can be dampened. Thus, the carbon that absorbs the gases is being tested and it seems that the results are being good.

In any case, the survival of plastic is not easy, but researchers are trying. In addition, experts expect great work in the future, as we currently use many types of plastics and do not know what will happen to them over time. Therefore, these can also surprise museum managers and collectors. It seems that nothing is forever, at least plastic!

Published in Deia.