## Materials Science and Engineering: An Introduction

$M_{n} = 6.31 \times 10^{5} g/mol$
Given: For polypropylene, $m= 42.08 g/mol$. Required: The number-average molecular weight for a polypropylene for which the degree of polymerization is 15,000. Solution: Using Equation 14.6: $M_{n} = (DP)(m) = (15,000)(42.08 g/mol) = 6.31 \times 10^{5} g/mol$