Compute the number-average molecular weight for a polypropylene for which the degree of polymerization is 25,000.

Given:

Propylene is

Degree of polymerization, = 25000

Solution:

no. of carbon atoms, = 3

no. of hydrogen atoms, = 6

atomic weight of carbon, =12.01 g/mol

atomic weight of hydrogen, = 1.008 g/mol

molecular mass of propylene, m =

m = g/mol

Now,

=  

= m( )

=

= 1052000 g/mol

where,

=  number-average molecular weight

answer: 500 wph.

explanation: