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In this work, the polymerization of limonene oxide (LO) has been optimized at room temperature with two different aluminium-based catalysts [AlMeX{2,6-(CHPh2)2-4-tBu-C6H2O}] (X = Me (1), Cl (2)). A fully bio-based ether, polylimonene oxide (PLO), has been synthesized with low molecular weight and good thermal stability, being a potential sustainable polymeric additive for other bio-based and biodegradable polymers such as polylactic acid (PLA). Hence, we have explored its ability to influence the thermal, mechanical and morphological properties of PLA by preparing their blends by melt processing. The addition of a low amount of PLO led to a nearly 10 °C decrease in the PLA glass transition temperature. Moreover, a decrease in the PLA melting temperature and the degree of crystallinity was observed. Interestingly, a remarkable increase in the flexibility of PLA-based films was noticed. All the results point to the existence of strong interactions between the components, suggesting their partial miscibility.

A recently reported combined polymerization process of glycidyl methacrylate, mediated by homometallic and heterobimetallic aluminium complexes, naturally produces nano-sized macromolecular assemblies. In this work, the morphological features and the rheological properties of these novel nanoassemblies are studied. The hydrodynamic sizes of the nanoparticles in the solution range from 10 to 40 nm (in numbers), but on a flat surface they adopt a characteristic thin disk shape. The dynamic moduli have been determined in a broad range of temperatures, and the time—temperature superposition applied to obtain master curves of the whole viscoelastic response from the glassy to the terminal regions. The fragility values obtained from the temperature dependence are of m ~40, typical of van de Waals liquids, suggesting a very effective packing of the macromolecular assemblies. The rheological master curves feature a characteristic viscoelastic relaxation with the absence of elastic intermediate plateau, indicating that the systems behaved as un-entangled polymers. The analysis of the linear viscoelastic fingerprint reveals a Zimm-like dynamics at intermediate frequencies typical of unentangled systems. This behaviour resembles that observed in highly functionalized stars, dendrimers, soft colloids and microgels.

A recently reported combined polymerization process of glycidyl methacrylate, mediated by homometallic and heterobimetallic aluminium complexes, naturally produces nano-sized macromolecular assemblies. In this work, the morphological features and the rheological properties of these novel nanoassemblies are studied. The hydrodynamic sizes of the nanoparticles in the solution range from 10 to 40 nm (in numbers), but on a flat surface they adopt a characteristic thin disk shape. The dynamic moduli have been determined in a broad range of temperatures, and the time—temperature superposition applied to obtain master curves of the whole viscoelastic response from the glassy to the terminal regions. The fragility values obtained from the temperature dependence are of m ~40, typical of van de Waals liquids, suggesting a very effective packing of the macromolecular assemblies. The rheological master curves feature a characteristic viscoelastic relaxation with the absence of elastic intermediate plateau, indicating that the systems behaved as un-entangled polymers. The analysis of the linear viscoelastic fingerprint reveals a Zimm-like dynamics at intermediate frequencies typical of unentangled systems. This behaviour resembles that observed in highly functionalized stars, dendrimers, soft colloids and microgels.

The antimicrobial lysozyme (Lys) was electrostatically incorporated to negatively charged crosslinked poly(glycidyl methacrylate) (c-PGMA) macromolecular assemblies. The resulting material was characterized by AFM, infrared spectra, water contact angle measurements and the staining with the primary amino specific dye fluorescamine. c-PGMA nanoparticles were successfully loaded with Lys reaching ratios of 27.3 ± 4.0 and 22.5 ± 1.7 mg Lys/g polymer for c-PGMA suspensions and functionalized glass substrates, respectively. Lys-loaded c-PGMA caused clear inhibition zones on S. aureus and E. coli in comparison to neat c-PGMA. c-PGMA functionalized surfaces were intrinsically resistant to colonization, but the incorporation of Lys added resistance to bacterial attachment and allowed keeping surfaces clean of bacterial cells for both strains. A relatively rapid release (24 h) of Lys was observed at physiological pH (7.4). In addition, c-PGMA functionalized substrates could be reloaded several times without losing capacity. c-PGMA macromolecular assemblies did not display cytotoxicity to human dermal fibroblasts as shown in 24 h MTT assays. This work demonstrated that c-PGMA assemblies display durable antibacterial activity, biocompatibility, and full reloading capacity with antimicrobial peptides. c-PGMA functionalized materials have potential application as nanocarriers for anti-infective uses.

New aluminium-alkali metal heterometallic compounds using the bulky ligand OAr = 2,6-bis(diphenylmethyl)-4-tert-butylphenoxide have been synthesized and characterized. The species obtained, [MAlMe (OAr)] (M = Li(2a), Na(2b), K(2c)) and [MAlMe (OAr) ] (M = Li(3a), Na(3b), K(3c)), include some of the few heterobimetallic examples of aluminate complexes with O-donor ligands described so far. Their activity in polymerization towards a difunctional monomer, such as Glycidyl Methacrylate (GMA), was evaluated. The compounds were revealed to be able to polymerize the acrylate groups via vinyl polymerization. Interestingly, the homometallic counterparts [AlXMe(OAr)] (X = Cl, Me), previously described by us, are very active in ROP processes of GMA. The combined polymerization process using both catalysts has also been explored to obtain a polymeric material with an exciting macromolecular architecture.