10.3 Plastic Sulfur


Chemical Concepts Demonstrated: Sulfur chemistry, polymers

Demonstration:

  • Heat sulfur in a small porcelain casserole until it melts
  • Pour the molten sulfur into a beaker of water

Observations:

    The newly solidified sulfur (now ropelike) is capable of stretching and bending.

Explanation:

    Sulfur in its yellow, powdery form is an octahedral ring.  Heat breaks up this ring.  When the molten sulfur is cooled by immersion into water, it forms a series of covalent bonds, or chains, much like a carbon polymer.  This chain structure is one of the primary reasons why polymers have the physical properties that they do.   It is interesting to note that the ability of sulfur to form carbonlike chains is critical to the process of vulcanizing rubber.