Improved Route to Linear Triblock Copolymers by Coupling with Glycidyl Ether-Activated Poly(ethylene oxide) Chains

Polymers, vol. 15, pp. 2128

Abstract

Poly(ethylene oxide) block copolymers (PEOz BCP) have been demonstrated to exhibit remarkably high lithium ion (Li+) conductivity for Li+ batteries applications. For linear poly(isoprene)-b-poly(styrene)-b-poly(ethylene oxide) triblock copolymers (PIxPSyPEOz), a pronounced maximum ion conductivity was reported for short PEOz molecular weights around 2 kg mol−1. To later enable a systematic exploration of the influence of the PIx and PSy block lengths and related morphologies on the ion conductivity, a synthetic method is needed where the short PEOz block length can be kept constant, while the PIx and PSy block lengths could be systematically and independently varied. Here, we introduce a glycidyl ether route that allows covalent attachment of pre-synthesized glycidyl-end functionalized PEOz chains to terminate PIxPSy BCPs. The attachment proceeds to full conversion in a simplified and reproducible one-pot polymerization such that PIxPSyPEOz with narrow chain length distribution and a fixed PEOz block length of z = 1.9 kg mol−1 and a Đ = 1.03 are obtained. The successful quantitative end group modification of the PEOz block was verified by nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). We demonstrate further that with a controlled casting process, ordered microphases with macroscopic long-range directional order can be fabricated, as demonstrated by small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It has already been shown in a patent, published by us, that BCPs from the synthesis method presented here exhibit comparable or even higher ionic conductivities than those previously published. Therefore, this PEOz BCP system is ideally suitable to relate BCP morphology, order and orientation to macroscopic Li+ conductivity in Li+ batteries.

Authors 12

1. Daniel T. Krause corresponding

   Forschungszentrum Jülich · Helmholtz-Institute Münster

   Affiliation as printed

   Helmholtz Institute Münster, IEK-12, Forschungszentrum Jülich GmbH, Corrensstr. 46, 48149 Münster, Germany

2. Susanna Krämer

   Forschungszentrum Jülich · Helmholtz-Institute Münster

   Affiliation as printed

   Helmholtz Institute Münster, IEK-12, Forschungszentrum Jülich GmbH, Corrensstr. 46, 48149 Münster, Germany

3. Vassilios Siozios

   University of Münster

   Affiliation as printed

   MEET Battery Research Center, University of Münster, Corrensstr. 46, 48149 Münster, Germany

4. Andreas Johannes Butzelaar

   Karlsruhe Institute of Technology

   Affiliation as printed

   Karlsruhe Institute of Technology (KIT), Institute for Chemical Technology and Polymer Chemistry (ITCP), Engesserstraße 18, 76131 Karlsruhe, Germany

5. Martin Dulle

   Forschungszentrum Jülich

   Affiliation as printed

   Jülich Centre for Neutron Science (JCNS-1/IBI-8), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany

6. Beate Förster

   Forschungszentrum Jülich · Ernst Ruska Centre

   Affiliation as printed

   Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Physics of Nanoscale Systems (ER-C-1), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany

7. Patrick Théato

   Karlsruhe Institute of Technology

   Affiliation as printed

   Karlsruhe Institute of Technology (KIT), Institute for Chemical Technology and Polymer Chemistry (ITCP), Engesserstraße 18, 76131 Karlsruhe, Germany

   Soft Matter Synthesis Laboratory, Institute for Biological Interfaces 3 (IBG-3), Karlsruhe Institute of Technology (KIT), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany

8. Joachim Mayer

   Forschungszentrum Jülich · Ernst Ruska Centre · Jülich Aachen Research Alliance

   Affiliation as printed

   Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Materials Science and Technology (ER-C-2), Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Straße, Jülich 52425, Germany

   Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Wilhelm-Johnen-Straße, 52425 Jülich, Germany

9. Martin Winter

   Forschungszentrum Jülich · University of Münster · Helmholtz-Institute Münster

   Affiliation as printed

   Helmholtz Institute Münster, IEK-12, Forschungszentrum Jülich GmbH, Corrensstr. 46, 48149 Münster, Germany

   MEET Battery Research Center, University of Münster, Corrensstr. 46, 48149 Münster, Germany

10. Stephan Förster Aachen Institute of Physical Chemistry

    Forschungszentrum Jülich · RWTH Aachen University

    Affiliation as printed

    Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany

    Jülich Centre for Neutron Science (JCNS-1/IBI-8), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany

11. Hans‐Dieter Wiemhöfer

    Forschungszentrum Jülich · Helmholtz-Institute Münster

    Affiliation as printed

    Helmholtz Institute Münster, IEK-12, Forschungszentrum Jülich GmbH, Corrensstr. 46, 48149 Münster, Germany

12. Mariano Grünebaum

    Forschungszentrum Jülich · Helmholtz-Institute Münster

    Affiliation as printed

    Helmholtz Institute Münster, IEK-12, Forschungszentrum Jülich GmbH, Corrensstr. 46, 48149 Münster, Germany