End-of-life fishing gear in Spain: Quantity and recyclability.

European Commission has approached the challenge of End-Of-Life (EOL) fishing gear and Abandoned, Lost, or otherwise Discarded Fishing Gear (ALDFG) by focusing on circular economy. Current directives highlight the need to provide a proper management to EOL fishing gears, fostering their separate collection, transport, and treatment from a circular perspective. They also request Member States to set collection and treatment targets. However, this is far from being widely implemented in a coordinated manner. In the quest to explore the Spanish case, this contribution aims at providing insights on the amount and type of EOL fishing gear and management practices carried out in different Spanish ports, as well as recycling options for such gears. Data was collected through an online survey, interviews to stakeholders, and visits to ports. Composition, degradation and mechanical recyclability of EOL samples were assessed. Yearly, 1643 tonnes of EOL fishing gear (mainly nets) are discarded in Spanish ports from trawling (97.5%), gillnet/trammel nets (2.3%) and purse seine (0.2%) fisheries. High-density polyethylene (from trawling nets) is the most common discarded polymer, followed by polyamide 6 (from gillnets/trammel net and purse seine nets). EOL fishing gear management is diverse in Spain as it depends on the nature of the port (who governs it, either regional or national govern), special agreements between local fishers' guilds and waste managing companies, the waste managers in port, etc. Polyamide nets are degraded but in good condition to be recycled mechanically; for trawl nets chemical recycling is more suited due to their degraded state. Currently, few recycling companies exists in Spain that are engaged on mechanical recycling of EOL fishing gears, none in chemical recycling. Therefore, a more comprehensive analysis, coordination, and smart logistics are needed to make the collection and recycling of EOL fishing gear possible.

Morphological Analysis of Several Bamboo Species with Potential Structural Applications.

Bamboo constitutes a family of plants that are very promising and interesting as renewable materials for both large and small structure construction. To be used as an alternative to traditional materials; the understanding of its morphology and mechanical behavior is of crucial importance. As the distribution of fibers and vascular bundles differs for each type of bamboo; several bamboo types have been characterized: Phyllostachys aurea (PA), Arundinaria amabilis (AA) and Dendrocalamus strictus (DS). Morphological analysis has been performed by optical (OM) and scanning electron microscopy (SEM). Differences in density; surface morphology and wall thickness have been found. In fact; PA and AA have shown a great morphological regularity; while DS presents the greatest thickness; to the point that it can be considered full culm. The plant's own ducts constitute a very important factor for future impregnations and the optimization of mechanical properties for structure construction.

Improving the Efficiency for the Production of Bis-(2-Hydroxyethyl) Terephtalate (BHET) from the Glycolysis Reaction of Poly(Ethylene Terephtalate) (PET) in a Pressure Reactor.

The depolymerization process of PET by glycolysis into BHET monomer is optimized in terms of reaction temperature and time, by carrying out the process under pressure to be faster for reducing the energy required. Almost pure BHET has been obtained by working in a pressure reactor at 3 bar both at 220 and 180 °C after short reaction times, while for longer ones a mixture of oligomers and dimers is obtained. Depending on the potential application required, the obtention of different reaction products is controlled by adjusting reaction temperature and time. The use of a pressure reactor allows work at lower temperatures and shorter reaction times, obtaining almost pure BHET. To the best of our knowledge, except for microwave-assisted procedures, it is the first time in which pure BHET is obtained after such short reaction times, at lower temperatures than those usually employed.

Cellulose and Graphene Based Polyurethane Nanocomposites for FDM 3D Printing: Filament Properties and Printability.

3D printing has exponentially grown in popularity due to the personalization of each printed part it offers, making it extremely beneficial for the very demanding biomedical industry. This technique has been extensively developed and optimized and the advances that now reside in the development of new materials suitable for 3D printing, which may open the door to new applications. Fused deposition modeling (FDM) is the most commonly used 3D printing technique. However, filaments suitable for FDM must meet certain criteria for a successful printing process and thus the optimization of their properties in often necessary. The aim of this work was to prepare a flexible and printable polyurethane filament parting from a biocompatible waterborne polyurethane, which shows potential for biomedical applications. In order to improve filament properties and printability, cellulose nanofibers and graphene were employed to prepare polyurethane based nanocomposites. Prepared nanocomposite filaments showed altered properties which directly impacted their printability. Graphene containing nanocomposites presented sound enough thermal and mechanical properties for a good printing process. Moreover, these filaments were employed in FDM to obtained 3D printed parts, which showed good shape fidelity. Properties exhibited by polyurethane and graphene filaments show potential to be used in biomedical applications.

Microplastics in the Bay of Biscay: An overview.

Microplastics (MPs) are an environmental problem of growing concern, and several studies have defined the Bay of Biscay (BoB) as a marine litter accumulation area. To address the abundance of MPs in this region, a critical overview is presented compiling the research performed to date on the different water bodies, sediments and biota. The comparative assessment highlights high spatial and temporal variability in MP distribution. MPs appear in at least 50% of the samples in waters and sediments. Polypropylene, polyethylene, polyester and polystyrene are the most frequent polymers, with a significant predominance of fragments and fibres. The BoB can be considered a region with medium concentration of MPs. However, monitoring programmes are needed to compile data over time and thus evaluate the historical trends of MP pollution. The difficulty of comparing studies is highlighted, due to the use of different methodologies. Hence, the harmonisation of monitoring methods is urgently required.

Water Uptake Behavior and Young Modulus Prediction of Composites Based on Treated Sisal Fibers and Poly(Lactic Acid).

The main aim of this work was to study the effect of sisal fiber surface treatments on water uptake behavior of composites based on untreated and treated fibers. For this purpose, sisal fibers were treated with different chemical treatments. All surface treatments delayed the water absorption of fibers only for a short time of period. No significant differences were observed in water uptake profiles of composites based on fibers with different surface treatments. After water uptake period, tensile strength and Young modulus values of sisal fiber/poly(lactic acid) (PLA) composites were decreased. On the other hand, composites based on NaOH + silane treated fibers showed the lowest diffusion coefficient values, suggesting that this treatment seemed to be the most effective treatment to reduce water diffusion rate into the composites. Finally, Young modulus values of composites, before water uptake period, were predicted using different micromechanical models and were compared with experimental data.

Functional properties and in vitro antioxidant and antibacterial effectiveness of pigskin gelatin films incorporated with hydrolysable chestnut tannin.

The impact of the incorporation of 10% w/w of hydrolyzable chestnut tannin into pigskin gelatin (G) films plasticized with glycerol (Gly) on the physicochemical properties as well as the in vitro antioxidant and antibacterial effectiveness against food-borne pathogens such as Escherichia coli and Streptococcus aureus was investigated. A higher tendency to both redness (a*) and yellowness (b*) coloration characterized gelatin films incorporated with chestnut tannin. The reduced lightness (L) and transparency of gelatin-chestnut tannin films plasticized with 30% w/w Gly might be associated with certain degree of phase separation which provoked the migration of the plasticizer to the film surface. The incorporation of chestnut tannin and glycerol affected the chemical structure of the resultant films due to the establishment of hydrogen interactions between components as revealed by Fourier transform infrared spectroscopy. These interactions reduced gelatin crystallinity and seemed to be involved in the substantial decrease of the water uptake of films with tannin, irrespective of the glycerol level. Such interactions had minor effect on tensile properties being similar to those of the control films (without chestnut tannin) at the same glycerol level. Films modified with 10% w/w chestnut tannin showed significant (P < 0.05) 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, ca. from 0 ± 0.033 to 87.1 ± 0.002% for chestnut tannin-free and chestnut tannin-containing gelatin films. The limited inhibitory activity of films incorporated with 10% w/w chestnut tannin against the selected bacteria evidenced by disk diffusion method probably resulted from the interactions within the film restricting the diffusion of the active agent into the agar medium. The more modest protective effect observed against a Gram-positive bacterium (S. aureus) was also discussed.