Open Access

ARTICLE

Highly Stereoselective Polymerization of Racemic Lactide by Bimetallic Schiff Base Complexes

Zhiqiang Sun, Ranlong Duan, Han Zhang, Xuan Pang^*, Xianhong Wang, Xuesi Chen

Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China

* Corresponding Author:

Journal of Renewable Materials 2015, 3(2), 82-90. https://doi.org/10.7569/JRM.2014.634133

Received 21 November 2014; Accepted 14 January 2015;

Abstract

A series of bimetallic Salen aluminum (III) complexes with different steric substituents were synthesized. These complexes were used as catalysts to produce polylactide in the ring-opening polymerization of racemic lactide. A kinetic research of polymerization demonstrated that the steric substituents on the phenolate ring of the complexes had remarkable infl uence on the stereoselectivity and the polymerization activity. The highest stereoselectivity was obtained with bulky substituent on the ortho position of the salicylidene moieties. Kinetic studies using all these complexes indicated that the polymerizations were fi rst-ordered with respect to lactide monomers. All these complexes gave highly isotactic polylactides with controlled molecular weight and narrow molecular weight distributions.

---

Keywords

---