P-Cresol → Sodium p-methylphenolate

4-methylphenol (7.45 g, 0.069 mol) is dissolved in 10 mL THF to form a solution. All of this solution then is added dropwise to a suspension of sodium hydride (1.57 g, 0.065 mol) in 40 mL THF to form a sodium 4-methylphenoxide solution. All of the sodium 4-methylphenoxide solution then is added to the polymeric solution in the autoclave. The autoclave is sealed and heated to 150° C. to generate a pressure of 3.5 bar. After 30 hours, the autoclave is cooled to room temperature and the resulting product of substituted polymer in solution is concentrated via rotary evaporation by using the Buchi Rotavapor as described above, until viscous. Then, all of the viscous polymer solution is precipitated into 6 M aqueous HCl and the polymer precipitate allowed to air dry in a fume hood.