Bulk Organocatalytic Synthetic Access to Statistical Copolyesters from l-Lactide and ε-Caprolactone Using Benzoic Acid

Abstract : The development of synthetic strategies to produce statistical copolymers based on l-lactide (l-LA) and ε-caprolactone (CL), denoted as P(LA- stat-CL), remains highly challenging in polymer chemistry. This is due to the differing reactivity of the two monomers during their ring-opening copolymerization (ROcP). Yet, P(LA- stat-CL) materials are highly sought after as they combine the properties of both polylactide (PLA) and poly(ε-caprolactone) (PCL). Here, benzoic acid (BA), a naturally occurring, cheap, readily recyclable, and thermally stable weak acid, is shown to trigger the organocatalyzed ring-opening copolymerization (OROcP) of l-LA and CL under solvent-free conditions at 155 °C, in presence of various alcohols as initiators, with good control over molar masses and dispersities (1.11 < Đ < 1.35) of the resulting copolyesters. Various compositions can be achieved, and the formation of statistical compounds is shown through characterization by H, C, and diffusion ordered spectroscopy NMR spectroscopies and by differential scanning calorimetry, as well as through the determination of reactivity ratios ( r = 0.86, r = 0.86), using the visualization of the sum of squared residuals space method. Furthermore, this BA-OROcP process can be exploited to access metal-free PLA- b-P(LA- stat-CL)- b-PLA triblock copolymers, using a diol as an initiator. Finally, residual traces of BA remaining in P(LA- stat-CL) copolymers (<0.125 mol %) do not show any cytotoxicity toward hepatocyte-like HepaRG cells, demonstrating the safety of this organic catalyst.
Document type :
Journal articles
Complete list of metadatas

Cited literature [84 references]  Display  Hide  Download

https://hal-univ-rennes1.archives-ouvertes.fr/hal-02120885
Contributor : Laurent Jonchère <>
Submitted on : Thursday, July 18, 2019 - 10:12:08 AM
Last modification on : Thursday, July 18, 2019 - 10:20:01 AM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : 2019-10-09

Please log in to resquest access to the document

Identifiers

Citation

Leila Mezzasalma, Simon Harrisson, Saad Saba, Pascal Loyer, Olivier Coulembier, et al.. Bulk Organocatalytic Synthetic Access to Statistical Copolyesters from l-Lactide and ε-Caprolactone Using Benzoic Acid. Biomacromolecules, American Chemical Society, 2019, 20 (5), pp.1965-1974. ⟨10.1021/acs.biomac.9b00190⟩. ⟨hal-02120885⟩

Share

Metrics

Record views

24