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Environmentally friendly sucrose-based poly(ester-urethane)s were synthesized and characterized, and their stability and degradation behavior were assessed under three different aging conditions: thermal, ultraviolet (UV), and hydrolytic treatment. The specimens underwent thermal treatment in both hot and cold climates to simulate a temperate continental climate. The samples were thoroughly characterized to assess chemical and structural changes (FT-IR, TGA, and DSC) and surface modifications (contact angle measurements and AFM and SEM analyses), providing insights into surface morphology and wettability alterations. Mechanical testing was also performed to evaluate the retention rate of the strength and the elongation after the aging process. The results showed that the introduction of sucrose into the main chain of the polyurethanes protected the ester and urethane groups from environmental degradation. The best stability in all three degradation environments was achieved by PCL-poly(ester urethane) due to its higher degree of crystallinity. PCL-based polyurethane exhibited a fracture strength retention rate exceeding 85% under all aging conditions, while the weight ratio remained practically unchanged after hydrolytic degradation. Thus, the obtained polyurethanes may support the advancement of sustainable, eco-friendly materials for future industrial applications.

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With the development of science and technology, wearable electronics are increasingly widely used in medical, environmental monitoring, and other fields. Thus, the demand for flexible electrodes is increasing. The two-dimensional material Ti[sub.3]C[sub.2]T[sub.x] has attracted much attention in the manufacture of flexible electrodes due to its excellent mechanical and electrical properties. However, the brittleness of pure Ti[sub.3]C[sub.2]T[sub.x] films has become a major obstacle for their use as flexible electrodes in wearable devices. Therefore, solving the brittleness problem of flexible electrodes based on Ti[sub.3]C[sub.2]T[sub.x] while maintaining the excellent performance of Ti[sub.3]C[sub.2]T[sub.x] has become an urgent problem. To solve this problem, Ti[sub.3]C[sub.2]T[sub.x] was compounded with waterborne polyurethane (WPU), and a Ti[sub.3]C[sub.2]T[sub.x]-WPU composite film with a hierarchical structure was constructed by evaporation-assisted self-assembly. The Ti[sub.3]C[sub.2]T[sub.x]-WPU composite film not only retains the excellent electrical conductivity of Ti[sub.3]C[sub.2]T[sub.x] (100 S m[sup.−1]) but also has flexibility (20 MJ m[sup.−3]). Furthermore, the Ti[sub.3]C[sub.2]T[sub.x]-WPU composite film is applied to functional devices such as contact pressure sensors and non-contact proximity sensors. Finally, the Ti[sub.3]C[sub.2]T[sub.x]-WPU composite film wearable device demonstrates its practical application potential in the field of wearable devices.

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The objective of this study was to evaluate the thermal comfort and performance of broilers in their initial stage of development utilizing two different heating systems. The experiment was conducted in two sheds placed on a commercial farm. The heating systems were: indirect heating furnace and radiation heating drums. At the beginning of the heating phase the birds were confined in an area corresponding to 360 [m.sup.2] in shed 1 and 180 [m.sup.2] in shed 2, delimited by polyurethane curtains, allowing a density of 58.8 birds [m.sup.-2]. The variables: dry bulb temperature (Tdb), relative humidity (RH%) and temperature and humidity index (THI) were calculated. Measurements were performed using continuous reading data loggers at 15-minute intervals throughout the experimental period, which was a complete productive cycle for males. Differences were detected in the environmental variables during the period evaluated, as well as differences in performance were found as a function of the two heating systems. The heating system of the furnace presented UR ranging from 47-59% in relation to the drum system (5157%), besides providing a more constant temperature and providing a greater distribution of heating. On the other hand, the drum system provided greater weight gain in the animals. Keywords: chicks; heating; poultry; animal comfort. Objetivou-se comeste estudo avaliar o conforto termico e desempenho zootecnico de frangos de corte em seu estagio inicial de desenvolvimento em funcao utilizando dois sistemas de aquecimento distintos. O experimento foi conduzido em dois galpoes localizados numa propriedade comercial. Os sistemas de aquecimento foram: fornalha de aquecimento indireto e tambores de aquecimento por radiacao. No inicio da fase de aquecimento as aves foram confinadas numa area correspondente a 360 [m.sup.2] no galpao 1 e 180 [m.sup.2] no galpao 2, delimitada por cortinas de poliuretano, possibilitando uma densidade de 58,8 aves [m.sup.-2]. Foram avaliadas as variaveis Temperatura de bulbo seco (Tbs), umidade relativa do ar (UR%) e calculado o indice de temperatura e umidade (ITU). As medicoes foram realizadas com o uso de dataloggers de leitura continua da marca Hobbo em intervalos de 15 minutos, durante todo o periodo experimental, que foi de um ciclo produtivo completo para machos. Foram detectadas diferencas nas variaveis ambientais durante o periodo avaliado como tambem foram encontradas diferencas no desempenho zootecnico em funcao dos dois sistemas de aquecimento. O sistema de aquecimento por fornalha apresentou UR variando de 47-59% em relacao ao sistema de tambores (51- 57%), alem de proporcionar temperatura mais constante e proporcionar maior distribuicao de aquecimento. Por outro lado, o sistema de tambores proporcionou maior ganho de peso nos animais. Palavras-chave: frangos; aquecimento; avicultura; conforto animal.

The unique properties of self-healing materials hold great potential in the field of biomedical engineering. Although previous studies have focused on the design and synthesis of self-healing materials, their application in in vivo settings remains limited. Here, we design a series of biodegradable and biocompatible self-healing elastomers (SHEs) with tunable mechanical properties, and apply them to various disease models in vivo, in order to test their reparative potential in multiple tissues and at physiological conditions. We validate the effectiveness of SHEs as promising therapies for aortic aneurysm, nerve coaptation and bone immobilization in three animal models. The data presented here support the translation potential of SHEs in diverse settings, and pave the way for the development of self-healing materials in clinical contexts. The unique properties of self-healing materials hold great potential in the field of biomedical engineering. Here, the authors designed a series of biodegradable and biocompatible self-healing elastomers with tunable mechanical properties, and apply them to various disease models in vivo, including aortic aneurism, bone fracture and nerve amputation.

In recent decades, scientific interest has increasingly focused on sustainable and green polymers. Within this context, considerable efforts have been devoted to the synthesis and exploration of eco-friendly non-isocyanate polyurethanes (NIPUs) as alternatives to conventional polyurethanes (PUs), solving the problem of isocyanate toxicity and other environmental problems that existed. This review article highlights the synthetic pathways of NIPUs and identifies the potential hazards associated with their production and end-of-life (EoL) stages. While in the literature there are several reviews regarding the synthesis of NIPUs, the current work distinguishes itself by providing a comprehensive summary of the latest research on NIPUs, with a particular focus on their lifecycle management, recyclability, and the challenges that hinder their scalability for industrial-level production. Advances in NIPU synthesis have made them strong candidates for a diverse range of applications. This review underscores the most notable examples of these advancements, emphasizing their potential to drive sustainable polymer development.

Two billion peripheral intravenous catheters (PIVCs) are used globally each year, but optimal dressing and securement methods are not well established. We aimed to compare the efficacy and costs of three alternative approaches to standard non-bordered polyurethane dressings. We did a pragmatic, randomised controlled, parallel-group superiority trial at two hospitals in Queensland, Australia. Eligible patients were aged 18 years or older and required PIVC insertion for clinical treatment, which was expected to be required for longer than 24 h. Patients were randomly assigned (1:1:1:1) via a centralised web-based randomisation service using random block sizes, stratified by hospital, to receive tissue adhesive with polyurethane dressing, bordered polyurethane dressing, a securement device with polyurethane dressing, or polyurethane dressing (control). Randomisation was concealed before allocation. Patients, clinicians, and research staff were not masked because of the nature of the intervention, but infections were adjudicated by a physician who was masked to treatment allocation. The primary outcome was all-cause PIVC failure (as a composite of complete dislodgement, occlusion, phlebitis, and infection [primary bloodstream infection or local infection]). Analysis was by modified intention to treat. This trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12611000769987. Between March 18, 2013, and Sept 9, 2014, we randomly assigned 1807 patients to receive tissue adhesive with polyurethane (n=446), bordered polyurethane (n=454), securement device with polyurethane (n=453), or polyurethane (n=454); 1697 patients comprised the modified intention-to-treat population. 163 (38%) of 427 patients in the tissue adhesive with polyurethane group (absolute risk difference −4·5% [95% CI −11·1 to 2·1%], p=0·19), 169 (40%) of 423 of patients in the bordered polyurethane group (–2·7% [–9·3 to 3·9%] p=0·44), 176 (41%) of 425 patients in the securement device with poplyurethane group (–1·2% [–7·9% to 5·4%], p=0·73), and 180 (43%) of 422 patients in the polyurethane group had PIVC failure. 17 patients in the tissue adhesive with polyurethane group, two patients in the bordered polyurethane group, eight patients in the securement device with polyurethane group, and seven patients in the polyurethane group had skin adverse events. Total costs of the trial interventions did not differ significantly between groups. Current dressing and securement methods are commonly associated with PIVC failure and poor durability, with simultaneous use of multiple products commonly required. Cost is currently the main factor that determines product choice. Innovations to achieve effective, durable dressings and securements, and randomised controlled trials assessing their effectiveness are urgently needed. Australian National Health and Medical Research Council.

The environmental ubiquity of plastic materials generates global concern, pollution, and health problems. Microorganisms and enzymes with plastic biodegradation potential are considered as environmentally friendly alternatives to address these issues. Interestingly, polluted environments exert selective pressure on native microbial communities that have the metabolic capacity to tolerate and transform different contaminants, including plastics. A number of enzymes have been described as polyurethane degraders. However, some of them do not possess complete characterization or efficient degradation rates. Hence, there is still a need to identify and characterize efficient enzymes for application in green processes for plastic recycling. Here, we used an environmental DNA sample isolated from the sediments of a polluted river in Mexico (Apatlaco River), which was used to construct a metagenomic fosmid library to explore the metabolic potential of microbial communities for polyurethane biodegradation. Functional screenings were performed on agar media containing the polyester polyurethane Impranil DLN (Impranil), and positively selected fosmid DNA was identified and sequenced by Illumina. Bioinformatic analyses identified two Acinetobacter genes ( epux1 and epux2) encoding alpha/beta hydrolases. The genes were heterologously expressed to determine the capacity of their encoded proteins for Impranil clearing. Both Epux1 and Epux2 enzymes exhibited Impranil cleavage at 30 °C and 15 °C and ester group modifications were validated by infrared spectroscopy. Furthermore, the release of building blocks of the polymer was determined by GC-MS analysis, thus indicating their esterase/polyurethanase activity. Overall, our results demonstrate the potential of these novel bacterial enzymes for the hydrolysis of polyurethane with potential applications in the circular plastics economy.

Although significant advances have been achieved in dynamic reversible covalent and non-covalent bonding chemistries for self-healing polymers, an ultimate goal is to create high strength and stiffness commodity materials capable of repair without intervention under ambient conditions. Here we report the development of mechanically robust thermoplastic polyurethane fibers and films capable of autonomous self-healing under ambient conditions. Two mechanisms of self-healing are identified: viscoelastic shape memory (VESM) driven by conformational entropic energy stored during mechanical damage, and surface energy/tension that drives the reduction of newly generated surface areas created upon damage by shallowing and widening wounds until healed. The type of self-healing mechanism is molecular weight dependent. To the best of our knowledge these materials represent the strongest ( S f  = 21 mN/tex, or σ f  ≈ 22 MPa) and stiffest ( J  = 300 mN/tex, or E  ≈ 320 MPa) self-healing polymers able to repair under typical ambient conditions without intervention. Since two autonomous self-healing mechanisms result from viscoelastic behavior not specific to a particular polymer chemistry, they may serve as general approaches to design of other self-repairing commodity polymers. Different self-healing materials were developed in the past but development of mechanically robust and affordable self-healing materials with high strain and stiffness is challenging. Here the authors develop mechanically robust thermoplastic polyurethane fibers and films capable of autonomous self-healing under ambient conditions.