Preparação e caracterização de nanocompósitos com atividade virucida ao Covid-19

Abstract

During the recent pandemic, caused by the new coronavirus (SARS-CoV-2), the persistence of the virus was found on different surfaces, such as cardboards, stainless steel, copper, and plastics. Inside them, the plastic surfaces showed a longer period of infectivity, approximately 72h. The Poly(ethylene terephthalate) – PET plastic bottle industry is one of the main responsible for the production of plastic waste. In this way, this study has the objective to produce nanocomposites with virucidal properties through the addition of copper nanoparticles (NPCu) in composites produced with polymeric matrix of PET and post-consumer recycled PET (PCR PET) for applications in hospital plastic surfaces of high contact. The filaments were produced in an extruder, with different concentrations of mixtures and manufactured from the design of experiments of mixtures. The materials produced were characterized by microscopic (scanning electron microscopy (SEM) and transmission electron microscopy (TEM)), spectroscopic (Fourier-transform infrared spectroscopy (FTIR)) and thermal (thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)). The nanocomposites were molded by injection and the mechanical properties such as tension, elongation, modulus of elasticity and impact were evaluated. The studies of virucidal activity of the filaments were carried out according to the methodology described in the ISO 21702:2019 standard. The spectroscopic characterization allowed the identification of the polymer functional groups in all samples (pure components and nanocomposites). The TGA thermogravimetric curves showed the nanocomposites degradation from 438 ºC with mass loss between 86 and 88% for all samples. In the DSC results, the processes of glass transition, crystallization and melting were observed for all the nanocomposites, differentiating them from PET and PET PCR, where only one endothermic transformation (melting) was recorded. The mechanical tests revealed that most of the samples presented similar tensile profiles. Only two samples had an anomalous profile. Also, it was observed that PET PCR is more resistant to traction when compared to PET. Regarding the impact test, a small difference was observed between the impact resistance of PET and PET PCR and that the addition of NPCu in samples with concentrations of 1% and 0.33% had greater influence on impact resistance. The virucidal assay evidenced that samples CP1, CP2, CP3, CP4, CP5, CP10 and CP13 present efficiency against both viruses. The CP4 sample showed efficiency only for the MHV virus. The other samples (CP6, CP7, CP8, CP9, CP11 and CP12) did not show a relevant reduction for any of the viruses, that is, they were not efficient.