Abstract

Este trabajo se basa en el conocimiento obtenido a partir del análisis y modelización de diversos edificios realizados, a lo largo de los años, por Picharchitects, empresa pionera de la arquitectura sostenible en España. Las conclusiones muestran como la propia arquitectura, antes que la maquinaria añadida, es el vector principal en la obtención de edificios Nzeb y un parámetro determinante para la obtención de un modelo constructivo coherente en términos de calidad, coste y beneficio económico, en el contexto actual donde el sector de la edificación es responsable del 40% del consumo global de energía.

Abstract

Currently there is a need to develop more sustainable and renewable materials compromised with the environment. From these needs, hemp stalk has great potential because it is mostly a waste material. Moreover, hemp shives are a lightweight material with a high insulating property. This study aims to increase the knowledge in a material made solely from stalk and ECF (elementary chlorine free) bleached eucalyptus kraft pulp and a second 100% recycled material where the kraft pulp is replaced by recycled cardboard fiber, also a vegetable coating is added to protect against moisture. The hemp/fiber ratio influence is studied. Samples are evaluated in terms of mechanical behaviour (compression and shear), thermal and acoustic insulation. To study the thermal insulation, a testing camera is used where the heat transfer through the material is measured in order to study the thermal resistance. A Kundt tube is used in the acoustic insulation study to calculate the absorption of sound waves in a range from 0 to 6500 Hz. The results show that by increasing the percentage of hemp, the mechanical properties increase (compression and shear). Also, the eucalyptus pulp acts as a binder between the shives; nevertheless, if there is not enough, the material is not stable. Therefore, a maximum of 70 wt.% of hemp is recommended. In the case of thermal insulation, better thermal resistance is obtained in the case of 60 wt.% of hemp, while in acoustic insulation a higher percentage of hemp have a high performance, reaching attenuation values greater than 0.8 for frequencies greater than 1000Hz. The carboard sample improves the shear and acoustic insulation performance. The coating improves the thermal resistance but worsens the acoustic insulation.

Abstract

With fuel economy and lightweight design becoming ever more significant due to the current materials, resources and environmental crisis, the manufacture of polymer composites for automotive industry use has experienced a steady growth in the last years and is expected to keep growing in the coming years. This means that there is a vast range of different polymer composites available in the market, with their unique properties, manufacturing processes and materials imbedded in them, each with their own set of impacts on the environment throughout their whole life cycle. The end-of-life treatment of a composite determines a substantial fraction of its footprint on the planet, and advanced treatments, namely pyrolysis can be used to obtain high value added compounds such as hydrogen and other light fuels. This study aims to address and quantify the impacts associated with the manufacturing and end of life treatments of an experimental glass fibre mat reinforced thermoplastic composite and compare them with the impacts caused by materials currently used in the automotive industry. Life Cycle assessment methodology will be used to compare the environmental impacts of this new material with traditional glass fibre composites, natural fibre reinforced composites and other materials with similar mechanical properties.

Abstract

The industry decarbonization has become in a fundamental challenge for the industries such as automotive or wind power. In this way, the structural components lightening is one of the principal issues for material manufacturers. For this objective, the composites are a competitive alternative, due to their unique relation between their strength and weight. Among the different structural composite part fabrication processes, liquid composite moulding (LCM) is one of the most interesting, due to its efficiency in terms of costs, time and energy consumption.

In this sense, resins with fast cure and low viscosity are gaining attention, among them polyurethanes are of particular interest.

This family of polymers is characterized by its great versatility, among them high-performance thermosetting polyurethanes (PUR). The advantages offered by PUR-based technology are great fatigue resistance, low viscosity and fast cure. However, the commonly used PUR’s for structural applications have some environmentally drawbacks, such as their components petrochemical origin and their low recyclability. For this reason, the aim of this work was the development of a more sustainable PUR formulation with the required mechanical properties for structural applications and suitable processability for LCM processes. Because of that, this work has focused on the analysis, synthesis and characterization of new PUR formulations and also the manufacturing process simulation and optimization.

Abstract

Composite epoxy resin based structures are widely and increasingly used at aerospace sector. Conventional composite processing requires the use of pre-impregnated raw material that requires refrigerated storage and autoclave use for the component consolidation. ADS jointly with Mtorres and with Hexcel support, have been intensely involved in the development of a Dry fibre automatic lamination, Liquid resin infusion and oven consolidation technology process (shortly referred as LRI) which permits the elimination of this energy consuming steps in order to improve the sustainability and reduce manufacturing costs so as allowing an increasing component integration reducing structural weight.

A LRI integrated lower cover with spars and stiffening elements has been delivered by CBC for its integration into an Outer external wing box specimen for its test, scheduled as the latest Milestone of Clean Sky 2 AIRFRAME ITD project (supported also by IIAMS, MALTA, CERTERIN R&T projects). This specimen will be assembled through a jiggles process with the delivered thermoplastic Upper Cover. The full scale test will complete the testing pyramid after having completed the previous steps: coupon, detail, panel level.

This partial Lower cover demo so as the Full Scale test, in which it will be integrated, will contribute to the TRL6 maturity status of the technology. 

Abstract

The development of sustainable composites has become in a major strategy for different sectors, such as the offshore renewable energy industry.

Thermoset polyurethanes (PUR) offer some advantages for their use in structural composite parts, like their good thermal properties, adhesion with different types of fibers, ultra-fast curing, low viscosity and corrosion resistance, highlighting their resistance to fatigue and consequent durability. However, PUR have some environmental drawbacks, such as their petrochemical origin and low recyclability.

Consequently, biobased PUR (BIO-PUR) formulated based on polyols derived from vegetable oils have aroused keen interest. Moreover, it is possible to incorporate recycled monomers in their formulation, which are obtained from highly degraded plastics collected from the sea.

In addition, it is necessary to consider the PUR end of life to improve the composite sustainability. An interesting solution is the incorporation of dynamic bonds into the PUR network, with reversible capacity such as Diels-Alder, to improve the polymer recyclability.

Therefore, this work has focused on the development of a new formulation of BIO-PUR with the required mechanical properties for structural applications in the marine environment. In addition, the integration of recycled monomers and DA bonds have been explored to improve the circularity of the developed resin. To this end, aspects ranging from analysis and synthesis to the characterization of the resins have been covered.