Reaction #1909793

Reaction equation

3,3-diethoxypropanol

potassium naphthalene

→

potassium

3,3-diethoxypropanol

Solvents

THF

THF

Conditions

Procedure

In an argon atmosphere, a reactor was charged with 30 ml of THF, 0.147 g of 3,3-diethoxypropanol and 3.0 ml of 0.34 mol/l solution of potassium naphthalene in THF, which were stirred for 10 minutes at room temperature. A potassium compound of 3,3-diethoxypropanol was thus formed. To the resultant solution, 7.04 g of ethylene oxide was added, and the resultant mixture was stirred at room temperature and at 1 atm. The resultant solution was allowed to react for two days, and then, 26.0 ml of 1.92 mol/l solution of DL-lactide in THF was added, and the resultant mixture was further stirred for two hours. Then, 3.1 g of methacrylic anhydride was added, and the resultant mixture was stirred for two days at room temperature. The resultant solution was poured into cooled 2-propanol, and the thus formed polymer was precipitated. The precipitate which was isolated by centrifugation was purified by freeze drying from benzene, with a yield of 11.48 g (79.4%). According to GPC and 1H-NMR, polyethylene glycol (PEG) segment, polylactide (PLA) and block copolymer had each a molecular weight of 5800, 4000 and 9800.

Source