Poly(methyl methacrylate) has the repeat unit $- [CH X_{2} - C (CH X_{3}) (COOCH X_{3})] X^{-}$ (formula $C X_{5} H X_{8} O X_{2}$ ; C 12, H 1, O 16). A sample has a molar mass of $183700 g mo l^{- 1}$ . Ignoring end groups, find the degree of polymerisation (number of repeat units per chain) as an integer.

Numerical answer type, answer in repeat units, tolerance 0.5.

Answer: 1837 repeat units

Repeat-unit mass

= 5 (12) + 8 (1) + 2 (16) = 100

. Degree of polymerisation

= 183700/100 = 1837