Alkaline hydrolysis of modified poly(l-lactide) monolayers

In this work, hydrolysis of biodegradable poly(l-lactide) (l-PLA) and copolymers of l-lactide (l-LA) and (benzyloxycarbonyl) methyl mophorline-2,5-dione (BMD) was investigated at the air/water interface. In order to improve the hydrophilicity of l-PLA, small amounts of BMD were copolymerized with l-LA. NaOH was used to adjust the pH of the subphase water. Under the conditions studied here, polymer monolayers showed much faster hydrolysis as either a subphase pH or the concentration of BMD in the copolymer is increased. This result was explained by increasing numbers of base attack sites per unit area and increasing hydrophilicity.