In 1969 scientist Paul F. Bruins wrote the following in the preface to the book Polyurethane Technology:

“Polyurethane technology is both a science and an art. Remarkable advances have been made in the past few years in both areas, thus creating the need for a review of the present state of knowledge and a projection into future developments.”

During my research into the conservation of plastics, particularly polyurethanes, I observed that 40 years later, they are even more widely used in science and art than when the above was written. Polyurethanes with tailor-made properties have been developed, and numerous applications...

Polyurethanes (PUR) are a family of plastics with different compositions and numerous applications, including cellular materials (flexible and rigid foams), fibres, soft and hard rubber (elastomers), surface coatings and adhesives. Polyurethanes are formed by the reaction of adiol(alcohol with two reactive hydroxyl groups) or apolyol(an alcohol with more than two reactive hydroxyl groups per molecule) with adiisocyanate(cyanate with two reactive sides) or apolyfunctional isocyanate(with more than two reactive sides) in the presence of suitable catalysts and additives (Bruins 1969).

Polyurethanes can be found as thermoplasts, thermosets and rubber (elastomeric) materials.

Thermoplastic polyurethanes...

The history of polyurethanes dates back to the chemistry of isocyanates in the year 1849, when Würtz reported the synthesis of isocyanate. It was not until after 1945, however, that the synthesis of isocyanates became commercially important for the polyurethane industry. The simple reaction of an alcohol and an isocyanate results in the formation of an urethane linkage (1).

Polyurethanesare formed by the reaction of a polyol (an alcohol with at least two reactive hydroxyl groups per molecule) with a diisocyanate or a polymeric isocyanate. The most widely used method for the preparation of polyurethane is the additional reaction...

Ever since polyurethane foams first became available, artists have had a great appreciation for this ‘new’ material. Nowadays, we find ourselves confronted with the limited durability of the early polyurethaneetherandesterfoams: loss of resilience, cracking, crumbling and powdering.

From 1990 onwards, conservators carried out consolidation of flexible pur foam using various consolidating agents as a curative method on degraded objects, thus expecting to slow down or inhibit degradation.

As long as polyurethane foam has not lost its structural integrity, objects can in some cases be restored using traditional techniques that have proven their suitability and are reversible....

It is a known fact (see also Chapter 2, degradation) that polyetherurethanes are more sensitive to oxidation and photo-degradation than polyesterurethanes. A higher resistance to light can be achieved by incorporating antioxidants and uv absorbers. The best light-resistant polyurethanes are those made from polyester and an aliphatic diisocyanate. As it progressed, the icn research project began to confirm that polyurethaneesterfoam is generally more sensitive to hydrolysis whereas polyurethaneetherfoam is more sensitive to oxidation. Test samples of polyurethane foam were subject to artificial light and thermal ageing. Samples (5 x 5 cm) were cut from...

Polyurethane foam used in modern and contemporary art works and design objects eventually degrades, thus confronting curators and conservators with the consequences of the limited durability of these materials: brittleness, crumbling, disintegration, deformation, cracking, delaminating and discolouration. Open (flexible) foams as well as closed (rigid) foams have a limited lifespan. In order to predict the longevity of both polyurethaneesterandetherfoam, the current condition and rate of decay of the object need to be ascertained. Two decades of conservation research at icn have shown that these two parameters depend on the composition, production method and added anti-ageing components,...

In the 1960s, Piero Gilardi was a young Italian artist² nourished by American Pop Art, Italian Arte Povera and European New Realism. These art movements were inspired by industrial production methods and the growing consumption of industrial goods in daily life. Artists belonging to these movements used quick and immediate techniques, and their materials were picked up on the shelves of the supermarket or manufactured objects that they recycled. The work of art placed these objects in a new perspective and in some cases gave them a playful dimension.

In 1965, Piero Gilardi began to make his Nature Carpets from...