Three aluminum alkyl complexes bearing porphyrin derivatives were synthesized by pyrrole derivatives and benzaldehyde derivatives. These complexes were characterized by NMR and elemental analysis. These complexes are used for racemic-lactide polymerization. In the ring-opening polymerization of racemic lactide, complex 3(2,3,7,8,12,13,17,18-octamethyl-5,10,15,20-tetraphenylporphyrin aluminum methyl, R-1=H, R-2=Me in Scheme 2) with isopropanol showed the highest stereoselectivity, and an isotactic polylactide with a P-m of 0.68 was obtained. The polymerization kinetics with complex 3 as catalyst was studied in detail. The kinetics of the polymerization data indicated that the rate of polymerization initiated by complex 3 had first-order dependency on monomer and catalyst. There is a linear relationship between lactide conversion and the number average molecular weight of PLA.
[1]Changchun Univ Sci & Technol, Sch Mat Sci & Engn, Changchun, Jilin, Peoples R China.
[2]Jilin Univ, China Japan Union Hosp, Dept Blood Transfus, Changchun, Jilin, Peoples R China.
[3]Minist Educ, Engn Res Ctr Optoelect Funct Mat, Changchun, Jilin, Peoples R China.
[4]Chinese Acad Sci, Changchun Inst Appl Chem, Key Lab Polymer Ecomat, Changchun, Jilin, Peoples R China.
(8.0+极速模式)