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The annual worldwide production of coffee exceeds 10 million tons, and more than 90% of this production is waste, including the husk. On the other hand, plastic consumption increases every year, and sustainable alternatives are necessary to decrease it. This work arises to solve these two problems, and seeks to produce products at an industrial level from polyethylene/coffee husk eco-composites. Both Low Density Polyethylene and High Density Polyethylene were used, and the amounts of coffee husk added as filler were 20 and 40 wt%. The composites were characterized by different morphological, thermal and mechanical techniques. Scanning Electron Microscopy images showed husk particles embedded in the polymer matrix, but with some gaps between the polymer and the filler, because no compatibilizer agent was used. The addition of large amounts of natural filler negatively affected the tensile strength and elongation at break, but increases eco-composites crystallinity, and hence, their Young modulus and hardness. The industrial applicability of the eco-composites was verified through the production of five different consumer products by extrusion and injection processes, using mixtures with 40 wt% coffee husks. All products were obtained without significant defects. If only 3.25 wt% of the polyethylene products produced each year in Colombia did so with the eco-composites developed in this work, all the coffee husk produced in the country would be used, and the emission of about 5.390 million m3 of greenhouse gases would be avoided.

The space holder process (SHP) is a useful and common technique to obtain metal foams. However, an important question remains unsolved: Would the quality of the salt affect the properties of the aluminum foam obtained? In this paper, removable preforms of two types of salt (refined and unrefined) were infiltrated with A356 aluminum alloy to obtain metal foams with different pore sizes. The interaction preform-metal was studied from analyzing the morphological structure of the foams, the metal microstructure, and the corrosion resistance of the Al356 alloy. It was observed that, although the two types of salt exhibited some differences, they did not show variations in relation to the porous structure and metal microstructure in the aluminum foams obtained. Additionally, the electrochemical analyses did not show significant effects on the corrosion behavior of aluminum foams caused by the interaction with the salt preforms.

Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 11190841 Program VID UI 003/2018

To face current sustainability challenges, we need to continue building, sharing, and applying the best possible knowledge to continue collaboratively developing solutions that allow us to improve how we live on our planet. In this, universities and other educational institutions have a crucial role in research, teaching, and service within the academic community and beyond. In this role, educational institutions also contribute to building and strengthening technical and relational human capabilities. It enables people to understand rationally better and emotionally connect more deeply with sustainability challenges and the diverse ways to continue solving them. In strengthening capabilities to respond to sustainability challenges, the contribution of a diverse range of areas of knowledge is required in the learning dynamics. Some areas of expertise that have been known for their human-centered approach to innovation processes4, such as architecture and design, play a significant part in the search for ideas that propose new ways to meet the challenges of sustainability while promoting well-being for people and other life forms and the environment. From architecture and design, the range of possibilities to develop ideas is broad, ranging from the proposal of new products, buildings, spaces, services and processes to recent activities and lifestyles.

Binary PEI/PBT blends are prepared using a two-step melt processing method. Miscibility study by MDSC and DMA reveals partial miscibility, and new evidence on the morphological evolution of PEI/PBT blends is presented. Two groups of blends are recognized: PBT-rich blends and PEI-rich blends, as well as phase inversion at concentrations close to 50 wt% of PEI. Mechanical, thermal, and flame resistance performance is influenced by blends morphology, and an opportunity for tailoring blends properties is recognized. Tensile modulus shows synergic contribution for 50/50 and 80/20 blends and yield strength is strongly affected by interfacial adherence between constituents. In addition, elongation at break is compromised by PBT-rich blends morphology, and by PEI-rich blends densification. The 50/50 blend exhibits the best elongational at break result due to its co-continuous morphology. Thermal stability and flammability tests reveal that PEI improves the thermal resistance and charring of PBT, particularly for 50/50 blend.

Blends between high-performance polymers (HPP) are barely studied, especially those produced by melting processing. In this work, it is proposed a novel methodology to prepare blends between polymers with notable processing temperature differences: poly(ether imide) (PEI) and poly(butylene terephthalate) (PBT). Processing parameters are settled after thermal and rheological evaluation of pure materials, those results suggest these blends need to be produced by steps. It is found a synergistic effect such as lowering PEI processing temperature and reducing PBT hydrolysis at high temperatures. Propose methodology allows to produce blends between HPP in the whole composition range with the same processing conditions.

Cellular metals are a new class of materials with promising applications and a unique combination of physical, chemical and mechanical properties. The Al-356 alloy is used to manufacture metal foams from NaCl preforms. Despite the usefulness of these materials, their performance may be affected by corrosion due to residual salt. This paper reports the study of the behavior of the Al-356 alloy in chloride solutions by electrochemical techniques in rotating disk electrode. The cathodic reaction of oxygen reduction is the crucial stage of process dissolution of the material, which shows that is the oxygen transport which limits the corrosion process.