Author : Dakshinamoorthy Deivasagayam
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (781 download)
Book Synopsis Titanium Complexes Based on Aminodiol Ligand for Ring Opening Polymerization of Cyclic Esters by : Dakshinamoorthy Deivasagayam
Download or read book Titanium Complexes Based on Aminodiol Ligand for Ring Opening Polymerization of Cyclic Esters written by Dakshinamoorthy Deivasagayam and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of titanium isopropoxides complexes coordinated by enantiopure, racemic, meso and diastereomeric aminodiol ligands have been prepared and characterized by spectroscopic techniques. The complexes were tested as initiators for the ring opening polymerization (ROP) of cyclic esters such as L/rac-lactide, caprolactone, butyrolactone and trimethylene carbonate via coordination-insertion mechanism. In lactide polymerizations, all complexes showed significant activity both in solution at 70°C and in bulk at 130°C with a good control. The complex derived from rac-aminodiol ligand gave partially heterotactic polylactide in ROP of rac-lactide, whereas all other complexes yielded atactic polylactides. For caprolactone polymerizations, all complexes were found to be effective initiators under both solution and bulk conditions (up to 60% monomer conversion was reached within 10 min in bulk condition at 70°C), again with good control. Kinetic studies of ROP of lactides and caprolactone in solution conditions have been investigated and showed a first kinetic order in monomer. Significant activities were also observed for (ROP) of butyrolactone and trimethylene carbonate. Block copolymers of caprolactone and lactides were successfully synthesized with these catalytic systems by sequential polymerization techniques. The complexes were also tested as initiators for the production of random copolymers containing caprolactone and lactides and a reverse order of reactivity was observed between lactide and caprolactone compared to homopolymerization.