Synthesis of High Molecular Weight Stereo-Di-Block Copolymers Driven by a Co-Initiator Free Catalyst

Carmen Moya-Lopez, Ivan Bravo, José A Castro-Osma, David Chapron, Patrice Bourson, Christelle Vagner, Marianne Cochez, Nils Leoné, Agustín Lara-Sánchez, Carlos Alonso-Moreno*, Daniel Hermida-Merino*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Stereo-diblock copolymers of high molecular weight polylactide (PLA) were synthetized by the one pot-sequential addition method assisted by a heteroscorpionate catalyst without the need of a co-initiator. The alkyl zinc organometallic heteroscorpionate derivative (Zn(Et)(κ3-bpzteH)] (bpzteH = 2,2-bis(3,5-dimethylpyrazol-1-yl)-1-para-tolylethoxide) proved to assist in the mechanism of reaction following a coordination-insertion process. Kinetic studies along with the linear correlation between monomer and number average molecular weight (Mn) conversion, and the narrow polydispersities supported the truly living polymerization character of the initiator, whereas matrix-assisted laser desorption/Ionization-time of flight (MALDI-TOF) studies showed a very low order of transesterification. The high stereo-control attained for the afforded high molecular weight derivatives was revealed by homonuclear decoupled 1H NMR spectra and polarimetry measurements. The nanostructure of the PLA derivatives was studied by both wide-angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) and the stereocomplex phase of the PLA stereo-diblock copolymers was successfully identified.

Original languageEnglish
JournalPolymers
Volume14
Issue number2
DOIs
Publication statusPublished - 7 Jan 2022

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