What are disadvantages of polyurethane and how Pepsen avoids them?

High Temperature and Build-up heat

Normal polyurethane can work long time under temperature 80 degree C, work temporarily under 120 degree C. It will also create a build-up heat easily when it is compressed back and forth frequently.

Pepsen special formulations can improve it, it can work long time under temperature 150 degree C, work temporarily under 200 degree C, it also improve build-up heat. The more important is ,it is not expensive.

Moisture and Hot Environments

Another limitation is that ester polyurethanes are subject to hydrolysis when in the presence of moisture, humidity and elevated temperatures. The combination of these factors will create a major problem for ester polyurethanes.

Ether based formulations can withstand hydrolytic attack if temperature is under 80 degree C. Most polyurethane can withstand continual contact with water for many years.

However, polyurethanes will degrade quickly when working environment including both moisture and hot temperature.

To extend working life, Pepsen can improve this by adding hydrolysis resistance additive or uses special polyether.

Strong Acid and Alkali

Urethane especially ester based polyurethane resists to many oils and chemicals such as petroleum-based materials , but very strong acids and alkali can damage urethane easily in short time, besides , it some solvents (the aromatic solvents).

Pepsen uses special ester and curative to improve this.

The photo shows hydro cyclone PU parts used under working condition including oils, outdoor high temperature and moisture.