10.1002/anie.202013562
Angewandte Chemie International Edition
COMMUNICATION
homopolymers and 50:50 and 75:25 polymer blends (Figures
S34–S35). However, DSC showed an increase in for the 50:50
blend (288 °C, ΔTm of +6–17°C compared with the parent
polymers, Figure 4 and Figure S43). In contrast, three melting
transitions were detected for the 75:25 blend, (Figure S44),
indicative of multiple crystalline phases. Conversely to the
homochiral polymers, WAXS analysis of the stereocomplex
displayed broad signals (Figure S47), indicative of significant
amorphous regions in the material or of very small crystalline
domains. The co-crystallization of poly(D-1) and poly(L-1)
remains to be optimized. However, to the best of our knowledge,
this is the first time that a stereocomplex of a polysaccharide
mimic is reported.
renewable monomer system may offer a new platform for the
development of stereoselective catalysts, and the renewable
materials with high Tg and Tm may find applications as hard blocks
of thermoplastic elastomers. We also report the formation of a
novel stereocomplex, with enhanced thermal properties
compared with its homochiral parents. Revealing the hydroxyl
groups of these polysaccharide mimics enables reversible cross-
linking, with potential applications in self-healing materials, as well
as post-polymerization functionalization, e.g. for the synthesis of
chiral macromolecular catalysts. Future studies will also focus on
the impact of polymer tacticity and the presence of an unnatural
sugar on the biocompatibility and biodegradation of these
materials.
Acknowledgements
Analytical facilities were provided through the Material and
Chemical Characterisation Facility at the University of Bath. We
thank the University of Bath HPC for computing resources, the UK
EPSRC (EP/N022793/1, DTP studentship for TMG), as well as
the Royal Society (RG/150538, UF/160021 fellowship to AB) for
research funding.
Keywords: carbohydrates • xylose • ring-opening polymerization
• polyether • polysaccharide mimic • stereocomplex •
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reaction with chlorodiphenylphosphine, while keeping the polymer
chain intact (Figures S49–S52).
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In conclusion, the chirality of xylose has been exploited to
modulate the properties of a family of carbohydrate polymers.
Produced by controlled anionic ROP of D- or L-anhydrosugar
derivatives, the homochiral and isotactic polyethers are
semicrystalline, whilst statistical copolymerization of both
enantiomers yields an atactic, amorphous material. This
4
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