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Aligned with the UN's Sustainable Development Goals (SDGs), self-healing elas- tomers stand out as a cutting-edge field in Rubber Science and Technology. These materials have the potential to reduce resource consumption, prolong the lifespan of infrastructure and products, and contribute to the Circular Economy. This study presents the development of bio-based self-healing elastomeric com- posites prepared from blends of epoxidized natural rubber (ENR) and cellulose propionate (CP) reinforced with cellulose fibers (CFs). The ENR/CP ratio was optimized, with a 70/30 ratio enhancing the tensile strength (TS) of the base rub- ber and slightly reducing the elongation at break. This blend demonstrated a TS healing efficiency of 75% after a temperature-driven healing protocol (200 bar at 150 C during 12 h). Then, the CF content was varied to enhance both mechani- cal performance and self-healing capabilities. Remarkably, from medium-high (5 phr to 15 phr) CF content, healing efficiencies higher than 85% were observed with important improvements in the mechanical performance. The self-healing process was attributed to the synergistic interplay between the polymeric chain mobility and the formation of hydrogen bonds. This innovative approach prom- ises materials with extended lifespans, mechanical robustness, and repairability, underscoring the commitment to SDGs 9, 11, 12, 13, 14, and 15.

In the field of soft robotics, current materials face challenges related to their load capacity, durability, and sustainability. Innova tive solutions are required to address these problems beyond conventional strategies, which often lack long-term ecological viability. This study aims to overcome these limitations using mechanically robust, self-healing, and recyclable ionic elastomers based on carboxylated nitrile rubber (XNBR). The designed materials exhibited excellent mechanical properties, including tensile strengths (TS) exceeding 19 MPa and remarkable deformability, with maximum elongations (EB) over 650%. Moreover, these materials showed high self-healing capabilities, with 100% recovery efficiency of TS and EB at 110 8C after 3 to 5 h, and full recyclability, preserving their mechanical performance even after three recycling cycles. Furthermore, they were also moldable and readily scalable. Tendon-driven soft robotic grippers were successfully developed out of ionic elastomers, illustrating the potential of self-healing and recyclability in the field of soft robotics to reduce maintenance costs, increase material durability, and improve sustainability.

The mechanical, thermal and gamma radiation attenuation properties of ethylene–propylene–diene monomer (EPDM)-based composites containing graphene nanoplatelets (GNs) and bismuth (III) oxide nanoparticles (B) were investigated. The use of polyethylene glycol (PEG) as a compatibilizer to improve the dispersion of the fillers was also investigated. The results showed that the combined use of these fillers resulted in a drastic increase in mechanical properties, reaching 123% and 83% of tensile strength and elongation at break, respectively, compared to those of EPDM. In contrast, the addition of PEG to composites containing EPDM GNs and B resulted in composites with lower values of mechanical properties compared to the EPDM/B/GN-based composite. However, the presence of PEG leads to obtaining a composite (EPDM/B/GNP) with a mass attenuation coefficient to gamma radiation (137Cs, 662 keV) superior to that composite without PEG. In addition, the composite EPDM, B and PEG exhibited an elongation at break 153% superior to unfilled EPDM. Moreover, the binary filler system consisting of 100 phr of bismuth (III) oxide and 10 phr of GN leads to reaching 61% of the linear damping coefficient of the EPDM composite compared to that value of the unfilled EPDM. The study of the morphology and the state of filler dispersion in the polymer matrix, obtained using scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively, provides a useful background for understanding the factors affecting the gamma radiation attenuation properties. Finally, the results also indicated that by adjusting the formulation, it is possible to tune the mechanical and thermal properties of EPDM composites reinforced with bismuth oxide and graphene nanoplatelets.

© 2011 Martín Gallego et al; licensee Springer. The work was supported by the Spanish Ministry of Science and Innovation (MICINN) under project MAT 2010-18749. MMG thanks the CSIC for a JAE-Pre grant., We employed an easy and direct method to measure the thermal conductivity of epoxy in the liquid (nanofluid) and solid (nanocomposite) states using both rodlike and platelet-like carbon-based nanostructures. Comparing the experimental results with the theoretical model, an anomalous enhancement was obtained with multiwall carbon nanotubes, probably due to their layered structure and lowest surface resistance. Puzzling results for functionalized graphene sheet nanocomposites suggest that phonon coupling of the vibrational modes of the graphene and of the polymeric matrix plays a dominant role on the thermal conductivities of the liquid and solid states., Spanish Ministry of Science and Innovation (MICINN), CSIC, Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

© 2005 Elsevier Ltd. The authors of this study gratefully acknowledge the financial support of the Ministry of Science and Technology (MCYT, Spain) through its project No PPQ2003-03299. Dr. López Manchado also acknowledges the concession of a Ramón and Cajal contract from the MCYT., The effects of silica and silane modified silica fillers on the pervaporation properties of poly (2,6-dimethyl-1,4-phenylene oxide) (PPO) dense membranes have been studied. Crystallinity, thermal and mechanical properties of unfilled and filled PPO membranes with silica and silane modified silica nanoparticles were investigated. The surface energy together with the solubility parameters of the membranes and the nanoparticles were determined. Pervaporation separation of methanol/methyl tert butyl ether (MTBE) mixtures over the entire range of concentration were carried out using both filled and unfilled membranes. The results are discussed in terms of the solubility and the diffusivity of each liquid component in the membranes. Flory-Huggins theory was used to predict the sorption methanol selectivity. Compared to the unfilled PPO membrane, the filled PPO membranes exhibit higher methanol selectivity and lower permeability. For methanol concentration in liquid feed mixture lower than 50 wt%, methanol selectivity of the filled PPO membranes with silane modified silica is better than that of the silica filled and unfilled PPO membranes., Ministry of Science and Technology (MCYT, Spain), Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

© 2006 Elsevier B. V. Conference of the European-Membrane-Society (2006. Giardini Naxos, Italy), Depto. de Estructura de la Materia, Física Térmica y Electrónica, Fac. de Ciencias Físicas, TRUE, pub

Los polímeros reforzados con fibras (FRPs) son materiales de altas prestaciones formados por fibras continuas o largas, hasta un 70 %, impregnadas en una matriz polimérica. Estos materiales tienen excelentes propiedades mecánicas, gran resistencia a la corrosión y a los agentes químicos, buena estabilidad térmica y gran ligereza, lo que explica su excelente relación resistencia-peso. Por todo ello, se utilizan cada vez más como materiales estructurales en una amplia gama de sectores como el transporte, la energía, la construcción, la industria y el deporte, entre otros. Sin embargo, estos materiales no están exentos de daños y su ciclo de vida es limitado. La demanda tecnológica actual exige materiales sostenibles para reducir la cantidad de residuos. Una alternativa es dotar al material compuesto de una capacidad de autorreparación, de modo que pueda repararse de forma autónoma cuando se dañe. Esta tesis tiene como objetivo el desarrollo de polímeros reforzados con fibra (FRPs) con capacidad autorreparadora a través del uso de mezclas poliméricas. Se utilizaron tres tipos de sistemas, dos de ellos basados en polímeros termoplásticos, poli(etileno-co-ácido metracrílico) (EMAA) y poli(metil metacrilato) (PMMA), y uno de ellos mediante el uso de un polímero superabsorbente, la poli(acrilamida-co-ácido acrílico) sal de potasio (SAP). La gran ventaja de usar mezclas poliméricas, frente a otros sistemas, es que es posible utilizar una resina termoestable comercial, lo cual hace que sea un método sencillo, económico y fácilmente escalable a nivel industrial..., Fiber-reinforced polymers (FRPs) are high performance materials usually made of continuous or long fibres, up to 70%, impregnated with a polymer matrix. These materials have excellent mechanical properties, high resistance to corrosion and chemical agents, good thermal stability, and great lightness, which accounts for their excellent strength-to-weight ratio. For all these reasons, they are increasingly used as structural materials in a wide range of sectors such as transport, energy, construction, industry and sports, among others. However, these materials are not exempt from damage and their life cycle is limited. The current technological demand requires sustainable materials to reduce the amount of waste. One alternative is to provide the composite material with a self-repairing capacity, so that it can be repaired autonomously when damaged. This Thesis aims to develop fiber reinforced polymers (FRPs) with self-healing capacity through the use of polymeric blends. Three types of systems were used, two of them based on thermoplastic polymers, poly(ethylene-co-methacrylic acid) (EMAA) and poly(methyl methacrylate) (PMMA), and one of them using a superabsorbent polymer, poly(acrylamide-co-acrylic acid) potassium salt (SAP). The great advantage of using polymeric blends is that a commercial thermoset resin (epoxy) is used, which makes it a simple, economical, and easily scalable method at an industrial level...

Among the most fruitful material-industry relationships is that of rubber and the automotive industry. Tires, seals, gaskets, hoses, tubes, soft, and damping parts are common applications in an industry that consumes more than 75 % of world rubber production. However, this relationship faces significant challenges. The difficulty of reprocessing rubbers due to their irreversible crosslinked network that ensures thermal stability, mechanical robustness and chemical resistance, makes them incompatible with the Circular Economy model. Numerous efforts are coordinated daily to overcome the Linear Economy model and achieve more environmentally friendly rubbers. Strategies like devulcanization, recycling, and self-healing are already being considered by several researchers and industries. Thanks to self-healing, a tire will be able to seal damage due to punctures or cracks. Thanks to self-healing, materials will be able to live longer and thus have an extended lifetime. This review delves into the key concepts of self-healing in the most commonly used elastomeric matrices in the automotive industry. While a more application-oriented approach is still necessary, the first steps have been taken towards future scalability in the sector. By analyzing the state-of-the-art taking into consideration the nature of the elastomeric matrix (natural or synthetic), as well as the different healing mechanisms (extrinsic, intrinsic and combinations), the chemistry behind them, and the mechanical performance, this review highlights the potential transformative impact of these concepts to revolutionize the industry and pave the way for a more sustainable future.

We describe a simple and scalable method for incorporating thermoplastic agents into fiber reinforced polymers (FRPs). Poly(ethylene-co-methacrylic acid) (EMAA) nanoparticles were successfully deposited on the surface of carbon fibers via spray coating. EMAA was finely distributed and exhibited strong adhesion to the fibers. The EMAA-coated carbon fibers improved the fracture toughness and provided the FRPs with self-healing ability. The resulting healing efficiency, based on the recovery of the interlaminar fracture toughness, was above 40 % and gradually decreased after three repair cycles. The repair mechanism of the system involves the inherent flow capacity of the thermoplastic and formation of interfacial bridging between the two damaged interphases. This methodology allows pure resin to be used without any chemical modification or adverse effects on its viscosity, and the coated fiber can be stored until use.

Self-healing materials offer a potential solution to the problem of damage to fibre-reinforced plastics (FRPs) by allowing for the in-service repair of composite materials at a lower cost, in less time, and with improved mechanical properties compared to traditional repair methods. This study investigates for the first time the use of poly(methyl methacrylate) (PMMA) as a self-healing agent in FRPs and evaluates its effectiveness both when blended with the matrix and when applied as a coating to carbon fibres. The self-healing properties of the material are evaluated using double cantilever beam (DCB) tests for up to three healing cycles. The blending strategy does not impart a healing capacity to the FRP due to its discrete and confined morphology; meanwhile, coating the fibres with the PMMA results in healing efficiencies of up to 53% in terms of fracture toughness recovery. This efficiency remains constant, with a slight decrease over three subsequent healing cycles. It has been demonstrated that spray coating is a simple and scalable method of incorporating a thermoplastic agent into an FRP. This study also compares the healing efficiency of specimens with and without a transesterification catalyst and finds that the catalyst does not increase the healing efficiency, but it does improve the interlaminar properties of the material.

Size-exclusion polymer electrolytes are promising charge carriers to diminish the crossover and allowing commercially available low-cost porous membranes in redox flow batteries. Boosting the solubility in water and maximizing the number of redox sites to enhance the capacity of these polymeric systems is challenging. New highly water dispersed amphiphilic diblock copolymers are reported here, with an average concentration value of 1.7 10 mmol of Ferrocene (Fc)-linked moieties per mg of polymer, determined by total X-ray reflection fluorescence. These redox amphiphilic block copolymers are stabilized in water as spherical nanoparticles (20 nm) by using a simple phase solvent inversion procedure. We evidence a maximum polymer dispersibility value of 6 g/L in water, for long-term stable polymer nanoparticle suspensions, yielding a theoretical capacity value of 4.78 mAh at 10.5 mM Fc. Further adjustment of the ionic conductivity and pH of these stable redox block copolymer suspensions has rendered a conductivity value of 44.5 mS/cm at pH values close to a neutral one, by adding a variety of salt supports. Studies using a 3-electrode configuration cell reveal an efficient charge transport between each of the Fc motifs in the polymer nanoparticle. A capacity value of 3.1 mAh with no transient of the polymer nanoparticles crosswise the cheap porous membrane is evidenced when cycled as polycatholyte material in a Zn hybrid aqueous redox flow battery. The particle size and electronic changes of these novel amphiphilic redox block copolymer electrolytes during consecutive redox cycles have also been monitored by dynamic light scattering and ultraviolet-visible spectroscopy, respectively. The analysis of the results enables the understanding of the main mechanisms behind their non-fully reversible capacity. Among them, aggregation and sedimentation, along with retention inside the graphite felt electrode acting the latter as a filter. These insights will aid the design of fut

El SMC (sheet molding compound) es un material compuesto comúnmente usado para fabricar piezas por un proceso de moldeo por compresión en caliente. Este compuesto cuenta con dos características claves para el sector de la automoción: permite producir piezas con una elevada cadencia y presenta una gran flexibilidad para el diseño de piezas de diversas formas y tamaños. Su gran inconveniente, como el de los materiales compuestos, en general, es que no se pueden reciclar y al final de su vida útil terminan almacenados en vertederos. En este trabajo, presentamos un nuevo SMC sostenible fácilmente reciclable mediante el uso de una resina termoplástica líquida patentada en el CSIC, SMC (sheet moulding compound) is a composite material commonly used to manufacture parts by a hot compression moulding process. This composite has two key characteristics for the automotive sector: it allows parts to be produced at a high rate of production and it has great flexibility for the design of parts of various shapes and sizes. However, like other composite materials, its primary drawback lies in the limited recyclability, resulting in their disposal in landfills at the end of their lifespan. In this work, we present a new and sustainable SMC using a liquid thermoplastic resin patented at CSIC

Product recycling reintroduces what is discarded as waste and minimizes the environmental impact on our society. Among the different types of waste from electrical and electronic equipment, toner recycling often falls short, downcycling plastic components. This study introduces an innovative approach in which waste parts from toner cartridges are valorized to develop (recyclable and) self-healing elastomeric composite materials. The synergy between carboxylated nitrile rubber (XNBR) as the elastomeric phase and high-impact poly (styrene) (HIPS) as the thermoplastic phase derived from toner cartridge waste was explored and optimized. This combination resulted in the creation of a thermoplastic elastomer exhibiting robust mechanical properties and self-healing capabilities with a tensile strength of 6.6 ± 0.2 MPa and a temperature-driven mechanical recovery of 100%. Furthermore, the capacity of toner powder, an integral component of waste, to act as a reinforcing filler was confirmed, with a 50% increase in mechanical strength compared with the unfilled composite. Moreover, an increase in toner content (up to 20 phr) resulted in an optimal balance between tensile strength and self-healing capacity, surpassing the traditional antagonism between these properties. As a result, this research opens a new pathway in the field of self-healing composites and suggests a practical and environmentally friendly approach for managing electronic waste, effectively supporting the principles of Circular Economy.

The present invention relates to spherical aggregates of semi-crystalline thermoplastic polyester, poly(cyclohexylene dimethylene terephthalate), with a size distribution of between 160 nm and 200 nm which fluorescence in the visible spectrum and are deposited on a thermoplastic aromatic polyester substrate or a thermoplastic polyolefin The present invention further relates to the process for obtaining said aggregates and to the use of said aggregates as a physically unclonable label, for identifying and/or tracing packaging for cosmetic products and/or perfumes. Therefore, the present invention could fall within the field of anti-counterfeit packaging, particularly in the area of anti-counterfeit packaging for cosmetic and/or perfume products.

In this work, we develop fluorosilicone elastomer (FSE) compounds with advanced properties by incorporating graphene oxides functionalized with vinyltrimethoxysilane (GO-V) and allyl isocyanate (GO-A). The morphology and structure of the graphene oxides were characterized confirming the successful functionalization, with contents of functional groups of 9.80 and 3.60% for GO-V and GO-A, respectively. The strong elastomer-graphene oxide interaction accelerates the crosslinking reaction and causes an important enhancement of the mechanical properties and thermal stability of composites. In addition, the swelling resistance to acid, base, and organic solvents is improved by more than 30%. These functional properties make FSE/GO composites a promising new class of advanced materials, expanding their potential application in edge technologies, spanning the manufacture of automotive components, aerospace and aviation parts, oil, gas, and petrochemical components, among others, particularly, seals, gaskets, valves and pipelines, or different components exposed to oil or solvent and high temperatures that require higher performance compared to conventional FSE products.

Until nowadays, the concept of the 3Rs (Reduce, Reuse, Recycle) has tried to develop responsible consumption habits. Nonetheless, the rise of ecological thinking has generated the appearance of four new Rs in addition to these basic 3Rs; the currently 7Rs (Reduce, Reuse, Recycle, Redesign, Renew, Repair and Recover) which refer to the actions necessary to achieve the change towards a circular economy (CE) model. This model aims at extending the lifetime of the resources through their rational and efficient use to generate value repeatedly, reducing costs and waste. In this review, we examine the route followed by tires from the CE perspective, analyzing end-of-life strategies that aim to improve the circular flow of tire rubber materials. We discuss the most relevant studies on the ‘‘7Rs” concepts applied to tires, comparing different scientific approaches, as well as their industrial and commercial implementation. We also illustrate the drawbacks and feasibility of each of the R-hierarchy strategies. From the early stages of production to the post-consumption step, the path that tires trail within this CE model evidences the commitment and efforts towards the development of effective management schemes for achieving a real sustainable mobility.