Repeating Units in Polychloroethene
Polychloroethene, also known as polyvinyl chloride (PVC), is a synthetic polymer made from the monomer chloroethene (commonly referred to as vinyl chloride).
The monomer unit of PVC is
CH2=CHCl, which contains a double bond and a chlorine atom attached to one of the carbon atoms.
Formation of the Repeating Unit
During the polymerization process, the double bond in the chloroethene monomer breaks, allowing the molecules to link together and form long chains. This process is called addition polymerization.
The resulting repeating unit has the structure:
Each repeating unit consists of:
[-CH2-CHCl-]Each repeating unit consists of:
- A methylene group (
-CH2-) - A chlorinated methine group (
-CHCl-)
Structural Representation
In the polymer chain, these units repeat in a linear fashion:
-CH2-CHCl-CH2-CHCl-CH2-CHCl-
Key Features
- The presence of chlorine gives PVC its flame-retardant and chemical-resistant properties.
- The repeating unit
[-CH2-CHCl-]determines the physical and chemical behavior of the polymer.
PVC is widely used in plumbing pipes, window frames, cable insulation, and medical devices due to its durability and versatility.