Synthesis of Grafted Polysilsesquioxane by Ring-Opening Polymerization of Lactide

The polysilsesquioxane having amino and phenyl groups (APSQ) was utilized as a macroinitiator for the ring-opening polymerization of L-(—)-lactide (LA). The combination of amino group on APSQ and a catalytic amount of the base, prepared from triazabicyclodecene and allyl isocyanate, enabled the efficient ring-opening polymerizations to afford the polysilsesquioxanes having the graft chains of poly(LA). The procedure was further applied to the introduction of the block copolymer of LA and ε-caprolactone (CL) into APSQ, in which the polysilsesquioxane having the graft chains of poly(CL) was used as the macroinitiator. These grafted polysilsesquioxane derivatives showed the characteristic thermal properties in the measurements of thermogravimetric analysis and differential scanning calorimetry.