The Advantages and Disadvantages of Polyurethane

The Advantages and Disadvanatges of Polyurethane

Polyurethanes were developed in Germany during World War II. Principal applications are in coatings, elastomers and foams. The elastomers have excellent abrasion resistance but high hysteresis; the associated heat build-up has limited their use in applications such as tires. Rigid polyurethane foams have become widely used as insulation materials because of their combination of low heat transfer and good cost effectiveness. Use as insulation and other applications are restricted by an upper temperature capability of about 250 F. Polyurethanes do not survive well in direct sunlight or in contact with most organic solvents. Two types are common: polyester based and polyether based, with these backbone structures actually comprising a significant part of a so-called polyurethane resin.

ADVANTAGES:

High abrasion resistance

Good low temperature capability

Wide molecular structural variability

Ambient curing possible

Comparatively low cost

DISADVANTAGES AND LIMITATIONS:

Poor thermal capability

Poor weatherability

Attacked by most solvents

Utilize toxic isocyanates

Flammable

TYPICAL APPLICATIONS:

Load-bearing rollers and wheels, acoustic damping materials, sporting goods, seals and gaskets. Very high usage in rigid and flexible foams, coatings, potting and encapsulation.