Plastic crystals were discovered in 1938 by J. Timmermans by their anomalously low melting entropy. He found that organic substances having a melting entropy lower than approximately 17 J·K·mol (~2Rg) are having peculiar properties. Timmermans named them .
Michils showed in 1948 that these organic compounds are easily deformed and accordingly named them, plastic crystals (). Perfluorocyclohexane for example is plastic to such a degree that it will start to flow under its own weight.