ABSTRACT
3D printing PLA wastes were recovered from a well-known reference grade and from different sources. The recovered wastes were subjected to an energic washing step and then reprocessed into films by melt-extrusion, followed by compression molding to simulate the industrial processing conditions. The obtained materials were characterized and the optical, structural, thermal and crystallization behavior are reported. The mechanical recycling process leads to an increase of the crystallinity and a decrease of the intrinsic viscosity of the formulations, particularly in the sample based on blends of different 3D-PLA wastes. Moreover, the obtained films were disintegrated under composting conditions in less than one month and it was observed that recycled materials degrade somewhat faster than the starting 3D-PLA filament, as a consequence of the presence of shorter polymer chains. Finally, to increase the molecular weight of the recycled materials, the 3D-PLA wastes were submitted to a solid-state polymerization process at 110, 120, and 130 °C, observing that the recycled 3D-wastes materials based on a well-known reference grade experiences an improvement of the intrinsic viscosity, while that coming from different sources showed no significant changes. Thus, the results show that 3D printing PLA products provides an ideal environment for the implementation of distributed recycling program, in which wastes coming from well-known PLA grades can successfully be processed in films with good overall performance.
ABSTRACT
The COVID-19 crisis has taken the world by surprise, and its effects are widening pre-existing inequalities such as socioeconomical, educational, and digital divides. The gender gap is no exception, and research shows that lockdowns are strongly impacting women, who, on the whole, are more vulnerable to the effects of a crisis. This study analyzes the impact of the COVID-19 lockdown in Spain on families, from a gender perspective. To this end, 663 participants related to the STEM (Science, Technology, Engineering, and Mathematics) fields were recruited to participate in the research through their connection with the Equality Office of the major technical university of Spain, Universidad Politécnica de Madrid, which offers most engineering and architecture degrees. The results indicate that the great myths of gender inequality are still alive in Spain, and that a crisis of this nature can perpetuate them. However, the crisis also presents an opportunity for change. Will the STEM careers be prepared to take advantage of this opportunity, or will this crisis end up perpetuating their markedly masculine character? Are we ready for a revolution? The COVID-19 crisis and its learnings about the importance of care can open the path to change.