Plastic sulphur

Plastic Sulphur

Green Bay High SchoolYear 12

RACHEL SONG

What is Plastic Sulphur ?

A form of rubber-like Sulphur - produced when molten Sulphur is rapidly poured

into cold water. (It is only produced with red molten Sulphur

that contains S8 chains.)

The S8 chain Sulphur cools too rapidly to allow the chains to reform into crowns and they lose energy while parallel to one another. This creates a structure with the chains all aligned but only held by the Van der Waals’ forces.

Plastic sulphur is unstable at room temperature, as the S8 chains slowly return to S8 crown molecules. The rubber-like structure gets more brittle as the crystals are slowly formed.

Steps of Change

Yellow solid (20ºC ~ 25ºC)

Yellow liquid (113ºC)

Dark & extremely viscous liquid (118 ºC)

Runny liquid at boiling point (445 ºC)

Yellow Solid

Yellow S8 Solid at room temperat-ure (20ºC ~ 25ºC)

Particle: Solid

Forces: Van der Waals’ force

Properties: powder

Yellow Liquid

Yellow S8 Liquid at melting point (113ºC)

Particle: Liquid


Properties: low viscosity

Dark brown & extremely viscous Liquid

Dark brown & extremely vis-cous S8 Liquid at 180ºC

Particle: Liquid


Properties: high viscosity

Runny Liquidat Boiling Point

Runny S8 Liquid at boiling point (445ºC)

Particle: Liquid


Properties: medium viscos-ity

Formation of Plastic Sulphur

Properties of Sulphur

Sulphur has various allotropic forms.

Below 95.6oC stable crystal form is rhombic. Above 95.6oC element transforms into a triclinic form. These crystalline forms both contain cyclic

S8 molecules. Above melting point (113oC) molten Sulphur is a yellow liquid containing

S8.

Sulphur Transformation

Properties of Sulphur

At 160oC Sulphur atoms form chains, liquid becomes more viscous & dark brown. At 180oC brown & viscous Sulphur liquid. At 200oC Sulphur chains shorten. At boiling point (445oC) viscous Sulphur becomes fluid again. Into the cold water (0oC ~ 20oC) liquid Sulphur rubber-like plastic Sulphur.

THANK YOU

Technology

Plastic sulphur