Question

The average molecular weight $({M_n})$of Teflon polymer is $1,20,000\,g/mol$. Find the Degree of polymerization.

Answer 1

The degree of polymerization, or DP, is the number of monomeric units in a macromolecule or polymer or oligomer molecule. There is only one type of monomeric unit in a homopolymer. :

Formula used: $D{p_n} = {X_n} = \dfrac{{{M_n}}}{{{M_0}}}$
Where $M_n$ is the number-average molecular weight and $M_0$ is the molecular weight of the monomer unit.

Complete step by step solution:
Teflon is an important element used in non-stick cookware utensils. Teflon is made of a chemical compound named polytetrafluoroethylene (PTFE). Teflon is produced by tetrafluoroethylene undergoing free radical polymerization.
Here, the number of average molecular weight $({M_n})$ of Teflon polymer $=$ $1,20,000$g/mol
In Teflon, the monomer used is $C{F_2} - C{F_2}$.
So, the molecular weight of $C{F_2} - C{F_2}$is ${M_0}$ $= 100$g/mol
The equation used for the degree of polymerization:
$\therefore$ $D{p_n}$ $= {X_n} = \dfrac{{{M_n}}}{{{M_0}}}$
Here, ${M_n}$ $= 1,20,000\,g/mol$ and ${M_0}$ $= 100\,g/mol$
${X_n} = \dfrac{{1,20,000}}{{100}}$
$= 1200$

Hence, the degree of polymerization of the Teflon is $1200$.

Note: Teflon is used as the coating for non-stick pans as Teflon is hydrophobic and has a high resistance capacity to heat. Because of high boiling point and a high melting point of Teflon, this chemical compound has fascinated scientists and students of science around the world. We can also find the degree of polymerization with the use of given equation for other polymers.