2.2.2.1. Synthesis of PLABz by protection of hydroxyl PLA groups
(reaction 1). In a first step the hydroxyl groups of PLA were protected
by benzoylation. For this purpose, PLA (5 g) and chloroform
(28 mL) were placed into a three-neck flask; 30 mL of toluene were
incorporated and the mixture was heated at 45 C under constant
stirring until complete dissolution. The benzoylation was carried
out with benzoyl chloride (0.3 mL) and pyridine (0.3 mL) at room
temperature during 24 h. Then, distilled water was added to induce
the precipitation. The mixture was filtered and removal of
unreacted chemicals was performed by repeated washing of the
products with hot water under sonication (10 min) followed by
filtering, until the residual water was completely clean.
The product, PLABz, was left at room temperature for 24 h and
then dried in a vacuum oven until further use