Characteristics of heterogeneous titanium alkoxide catalysts for ring-opening polymerization of lactide to produce polylactide

TiCl(O-i-Pr)3/SiO2 and Ti(O-i-Pr)4/SiO2 were prepared by immobilizing titanium(IV) chloride triisopropoxide (TiCl(O-i-Pr)3) and titanium(IV) tetraisopropoxide (Ti(O-i-Pr)4), respectively, over pretreated silica. A series of solution polymerizations of l-lactide were conducted with homogeneous alkoxide catalysts and silica-supported titanium alkoxide catalysts to compare their catalytic activity and the characteristics of the polylactide (PLA) produced. The conversion of l-lactide with the silica-supported alkoxide catalysts was higher than that with homogeneous catalysts even though the catalyst activity was low. In addition, the PLA produced using silica-supported alkoxide catalysts had a higher molecular weight and Tm than those produced with the homogeneous catalyst.

TiCl(O-i-Pr)3/SiO2 and Ti(O-i-Pr)4/SiO2 were prepared by immobilizing titanium(IV) chloride triisopropoxide (TiCl(O-i-Pr)3) and titanium(IV) tetraisopropoxide (Ti(O-i-Pr)4), respectively, over-pretreated silica for ring-opening polymerization of lactide to produce polylactide. The PLA produced using silica-supported alkoxide catalysts had a higher molecular weight and Tm than those produced with the homogeneous catalyst. Figure optionsDownload as PowerPoint slide