RESUMO
The purpose of this study is to investigate how to recycle FFP2 face masks used during Covid-19 pandemic without using previous sorting process and to characterize the properties of the material obtained. The way of splitting and processing the mixture of materials was studied as well as the final properties such as chemical, thermal and mechanical characteristics. The resulting recycled material is a blend of polymers with such mechanical and thermal properties that could be used as an alternative to recycled PP (polypropylene). Avoidance of previous sorting process gives the face mask recycling a new and simplified way of preventing this material to be disposed in environment and an opportunity of second life for the polymers they are made of. With this work we lay the basis to reduce the plastic pollution related with the recommended use of face masks during Covid-19 pandemic.
RESUMO
Stimuli-responsive polymer nanospheres of poly(4-vinyl pyridine) have been obtained using a very simple modified nanoprecipitation technique. This process is conducted without help of crosslinking or monomer polymerization, methods used until now for this purpose. The influence of the surfactant concentration used in the preparation on particle size, the stability and the swelling kinetics of these hydrogels are studied. Furthermore, the nanospheres are shown to be pH and ionic strength responsive, undergoing swelling with equilibration times in the range of days. Dynamic light scattering and scanning electron microscopy were used to determine the structure, size, dispersion and morphology of these materials. Due to their response to stimuli, these nanoparticles are of potential interest for a number of biomedical applications such as drug delivery or biosensors.
