Conductive polymers are organic polymers that conduct electricity.Such compounds may have metallic conductivity or can be semiconductors . The biggest advantage of conductive polymers is their processability, mainly by dispersion.
A dispersion is a phenomenon in which particles are dispersed in a
continuous phase of a different state.
Conductive polymers are generally not thermoplastics , i.e.
, they are not thermoformable. But, like insulating polymers, they are organic
materials. They can offer high electrical conductivity but do not show similar
mechanical properties to other commercially available polymers. The electrical
properties can be fine-tuned using the methods of organic synthesis and by advanced dispersion techniques.
Thermoplastics:
The polymer chains associate through intermolecular forces ,
which weaken rapidly with increased temperature, yielding a viscous liquid.
Thus, thermoplastics may be reshaped by heating and are typically used to
produce parts by various polymer processing techniques.
Organic synthesis is a special branch of chemical synthesis
and is concerned with the construction of organic compounds via organic
reactions .
Each step of a synthesis involves a chemical reaction, and
reagents and conditions for each of these reactions must be designed to give an
adequate yield of pure product.
The conductivity of such polymers is the result of several
processes. For example, in traditional polymers such as polyethylenes, the
valence electrons are bound in sp3 hybridized covalent bonds . Such
"sigma-bonding electrons" have low mobility and do not contribute to
the electrical conductivity of the material. However, in conjugated materials,
the situation is completely different. Conducting polymers have backbones of
contiguous sp 2 hybridized carbon centers. One valence electron on each center
resides in a p z orbital, which is orthogonal to the other three sigma-bonds.
All the pz orbitals combine with each other to a molecule wide delocalized set
of orbitals. The electrons in these delocalized orbitals have high mobility
when the material is "doped" by oxidation, which removes some of
these delocalized electrons. Thus, the conjugated p-orbitals form a
one-dimensional electronic band , and the electrons within this band become
mobile when it is partially emptied.