Question

The $P$ (PDI) of a polymer is :

$({\overline{M}}_w=$ weight average molecular mass and ${\overline{M}}_n=$ number average molecular mass)

• A. the product of ${\overline{M}}_n$ and ${\overline{M}}_w$
• B. the sum of ${\overline{M}}_n$ and ${\overline{M}}_w$
• C. the difference between ${\overline{M}}_w$ and ${\overline{M}}_n$
• D. the ratio between ${\overline{M}}_w$ and ${\overline{M}}_n$

Answer 1

The correct option is D the ratio between ${\overline{M}}_w$ and ${\overline{M}}_n$

The term polydispersity index represented by (PDI) refers to either molecular mass or degree of polymerization.

$PDI=\frac{M_w}{M_n}$

The ratio between $M_w$ and $M_n$

$M_w$ = weight average molecular mass.

$M_n$ = number average molecular mass.