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Polymers of ε-Caprolactone Using New Copper(II) and Zinc(II) Complexes as Initiators: Synthesis, Characterization and
Andrés F Posada1, Mario A Macías2, Santiago Movilla3
1Departamento de Química, Universidad de los Andes, Carrera 1 No. 18A-12, Bogotá 111711, Colombia. af.posada@uniandes.edu.co.
Abstract:
Five of six new Zn(II) and Cu(II) complexes were active in the ring-opening polymerization (ROP) of ε-caprolactone (CL) under solvent-free conditions, producing polycaprolactones (PCLs) of high crystallinity with molecular weights between 22,900 and 38,700 g mol-1 and decomposition temperatures above 260 °C. ¹H NMR analysis demonstrated that the PCLs obtained were mainly linear, having hydroxymethylene groups at the chain ends. The results obtained indicated a significant improvement in terms of the ratio of monomer:initiator compared to related Cu(II) and Zn(II) complexes. In addition, the structures of the complexes 1 and 4 were determined by single-crystal X-ray diffraction. The synthesis and full characterization of all complexes are described in this paper.
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