Employing (half‐)titanocene complexes as initiators for the synthesis of end‐functionalized polylactides by coordination polymerization

October 11, 2018

Title

Employing (half‐)titanocene complexes as initiators for the synthesis of end‐functionalized polylactides by coordination polymerization

Author

Georgios Patias, Ioannis Choinopoulos, Spyros Koinis, Marinos Pitsikalis

Year

2018

Journal

Journal of Polymer Science Part A: Polymer Chemistry

Abstract

Seven (half‐)titanocene alkoxide complexes, [Cp2TiCl(OEt)], [Cp2TiCl(O‐2‐Bu)], [Cp2TiCl(OCH2CF2CF2H)], [CpTiCl2(OEt)], [CpTiCl2(O‐(S)‐2‐Bu)], [CpTiCl2(OCH2CF3)], and [Cp2TiCl(OCH2CF3)], were synthesized and employed in lactide coordination polymerization. These organotitanium (IV) compounds proved to be very efficient initiators for the ring‐opening polymerization of enantiomeric l‐lactide and racemic mixture of rac‐lactide, leading to end‐functionalized polymers. Kinetic studies illustrated that these compounds produce well‐defined polymers in a controlled manner. This was further demonstrated by synthesizing poly(l‐lactide‐b‐hexyl isocyanate) diblock copolymer. The effect of the alkoxy end groups on the thermal behavior of the polymers was also studied by thermogravimetric analysis and differential scanning calorimetry. The polymers were characterized using size exclusion chromatography and proton nuclear magnetic resonance spectroscopy. The optical properties of the diblock copolymer were also investigated. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018

Instrument

J-815

Keywords

Circular dichroism, Cotton effect, Polymers, Stereochemistry, Optical properties