Epoxy Vitrimer Materials by Lipase-Catalyzed Network Formation and Exchange Reactions.

The preparation and reprocessing of an epoxy vitrimer material is performed in a fully biocatalyzed process wherein network formation and exchange reactions are promoted by a lipase enzyme. Binary phase diagrams are introduced to select suitable diacid/diepoxide monomer compositions overcoming the limitations (phase separation/sedimentation) imposed by curing temperature inferior than 100 °C, to protect the enzyme. The ability of lipase TL, embedded in the chemical network, to catalyze efficiently exchange reactions (transesterification) is demonstrated by combining multiple stress relaxation experiments at 70-100 °C and complete recovery of mechanical strength after several reprocessing assays (up to 3 times).

Lipase-Catalyzed Epoxy-Acid Addition and Transesterification: from Model Molecule Studies to Network Build-Up.

Commercially available lipase from (lipase TL) is investigated as a biocatalyst for the formation of an acid-epoxy chemical network. Molecular model reactions are performed by reacting 2-phenyl glycidyl ether and hexanoic acid in bulk, varying two parameters: temperature and water content. Characterizations of the formed products by H NMR spectroscopy and gas chromatography-mass spectrometry combined with enzymatic assays confirm that lipase TL is able to simultaneously promote acid-epoxy addition and transesterification reactions below 100 °C and solely the acid-epoxy addition after denaturation at > 100 °C.

Fabrication and characterisation of 3D printed MWCNT composite porous scaffolds for bone regeneration.

Carbon nanotubes (CNTs) with exceptional physical and chemical properties are attracting significant interest in the field of tissue engineering. Several reports investigated CNTs biocompatibility and their impact in terms of cell attachment, proliferation and differentiation mainly using polymer/CNTs membranes. However, these 2D membranes are not able to emulate the complex in vivo environment.

Thermal Diffusivity Mapping of Graphene Based Polymer Nanocomposites.

Nanoparticle dispersion is widely recognised as a challenge in polymer nanocomposites fabrication. The dispersion quality can affect the physical and thermomechanical properties of the material system. Qualitative transmission electronic microscopy, often cumbersome, remains as the 'gold standard' for dispersion characterisation.