Question $1$

Nylon $11$ has the following structure:

The average degree of polymerisation of a sample of Nylon $11$ is $96$ and $\frac{?}{\text{b}\text{a}\text{r}}(M{)}_w=118000\frac{g}{m}ol.$ What is the polydispersity of the polymer?

$[3]$

Question $2$

$($i$)$ Gel Permeation Chromatography $($GPC$)$ is used to determine the $M_w,M_{n,1},M_z$ and the molecular weight distribution $($MWD$)$ of a polymer. With the aid of a diagram, briefly explain the principle of molecular separation in this technique.

$[4]$

Cross Sectional view of a Porous Particle in a GPC Column

$($ii$)$ Calculate the number average molecular weight $(M_n)$ for a sample of polystyrene that contains equal weights of polymer having molecular weights of $30000,60000$ and $90000\frac{g}{m}ol.$

$[4]$