Poly(ethylene terephthalate) was depolymerised under supercritical ethanol, 98 wt% of diethylterephthalate was obtained after 45 min, by adding [Bmim][BF4] as catalyst.

[Hmim][HSO] ionic liquid (IL) and bio-renewable sources as chitosan (CHT) and chondroitin sulfate (CS) were used to yield hydrogel-based materials (CHT/CS). The use of IL to solubilize both polysaccharides was considered an innovative way based on "green chemistry" principle, aiming the production of CHT/CS blended systems. CHT/CS hydrogels were carried out in homogeneous medium from short dissolution times. The hydrogels were characterized and achieved with excellent stabilities (in the 1.2-10pH range), larger swelling capacities, as well as devoid of cytotoxicity towards the normal VERO and diseased HT29 cells. The CHT/CS hydrogels carried out in [Hmim][HSO] could be applied in many technological purposes, like medical, pharmaceutical, and environmental fields.

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Nanoparticles (NPs) based on N,N-dimethyl chitosan (DMC) and N,N,N-trimethyl chitosan (TMC), physical crosslinked with sodium tripolyphosphate (TPP) were successful obtained, using water/benzyl alcohol emulsion system. NPs morphologies were evaluated by Scanning Electron Microscopy and Transmission Electron Microscopy. NPs were characterized by Infrared Spectroscopy (FTIR), Thermogravimetric Analysis, Zeta Potential, Differential Scanning Calorimetry and Wide-angle X-ray Scattering. Curcumin (CUR) was loaded onto NPs and controlled release studies were evaluated in simulated intestinal fluid and in simulated gastric fluid. Cytotoxicity assays showed only loaded TMC/TPP particles containing CUR were slightly cytotoxic on human cervical tumor cells (SiHa cells), concerning unloaded TMC/TPP particles. Conversely, loaded NPs (TMC/TPP/CUR and DMC/TPP/CUR), especially TMC/TPP/CUR sample presented greater biocompatibility toward healthy VERO cells than unloaded NPs (TMC/TPP and DMC/TPP).

Using ethylene glycol (EG) and post-consumer poly(ethylene terephthalate) (PET) bottles, monomers and oligomers were obtained through glycolysis catalyzed by zinc acetate. Three reaction temperatures (150, 160 and 170 ∘ C) and water contents (0, 1.0 and 2.0% with respect to the volume of EG) were used as inputs; the extent of depolymerization as the analyzed response formed the basis for a factorial design experiment. The products obtained from PET glycolysis were analyzed using high-performance liquid chromatography and Fourier transform infrared spectroscopy, and their morphology was evaluated using scanning electron microscopy. The results showed the presence of terephthalic acid, hydroxylated tetramers, bis(hydroxyethyl) terephthalate monomer and dimer, and also oligomers with various molecular weights, water being present in the reaction medium. Statistical analysis (95% confidence) indicated that temperature and water content were significant inputs for glycolysis of PET, with the temperature being much the more important factor.