what is the functionality on Polymers?
State its significance :
(i) Mono functional
(ii) Bifunctional
(iii) Trifunctional
Answers
Answer :
The number of reacting sites present in a monomer is reffered as its funcionality.
An organic molecule acts as an monomer only when it possesses at least two reactive sites or bonding sites.
SIGNIFICANCE:
(i) Monofunctional :
Monofunctional polymers are unable to go under ploymerisation.
(ii) Bifuncional :
When a monomer has two bonding sites,it is is said to bi funcitional Monomer.
This form only linear or straight chain polymer.
This is because, in case of bifunctional monomer, the bonding groups attach side by side each other, resulting in the formation of large linear molecule.
In this, the monomer units are linked together through strong covalent bond whereas different chains by weak van der Waal's Force.
Due to presence of van der Waal's force their is no restriction on the movement
of one chain over other.
(iii) Trifunctional :
When a monomer has three bonding sites , it is said to trifunctional monomer.
The polymers formed in this are of three di-mentional network.
In this, the monomer units are linked together through strong covalent bond whereas different chains were also by covalent bonds.
Due to absence of van der Waal's force their is
an restriction on the movement of one chain over other.