Oxidised multi-wall carbon nanotubes–(R)-polylactide composite with a covalent β-d-uridine filler-matrix linker

Oxidised multi-wall carbon nanotubes (MWCNTs)–(R)-polylactide (PLA) composite was prepared in 85% yield via in-bulk Ring Opening Polymerisation (ROP) of (R,R)-lactide at elevated temperature using a ‘grafting-from’ technique. Outer nanotube walls were firstly covalently functionalised with a β-d-uridine linker—through the more reactive hydroxyl group (5′-OH)—enabling further a direct growth of the polymer from the free secondary hydroxyl groups (2′- and 3′-OH) present in the β-d-ribofuranose moiety. The morphology and chemical structure of the composite were comprehensively studied revealing a high-quality MWCNT-filler dispersion and loading of ca. 7 wt%, accompanied by a high molecular weight (Mw) of the (R)-PLA matrix equal to 116,700 Da. The presence of nanotube-filler affected the alignment of polymer fibrils in the composite. The elaborated approach may be implemented to a larger scale fabrication of biodegradable composites for medicinal applications or other functional materials where an enhanced matrix-filler interaction is required.

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► High yield synthesis of oxidised MWCNT–(R)-PLA composites via in-bulk Ring Opening Polymerisation of (R,R)-lactide using ‘grafting-from’ technique.
► An enhanced matrix-filler interaction achievable by employing a β-d-uridine linker containing hydroxyl groups of a different reactivity.
► High-quality MWCNT-filler dispersion and loading of 7 wt%.
► High Mw of the homochiral (R)-PLA matrix equal to 116,700 Da.
► A method expandable towards biocomposites for medicinal applications.