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A simple and straightforward addition or defluorination of α-(trifluoromethyl)styrenes with 2-nitroimino-imidazolidine (2a), 2-(nitromethylene)imidazolidine (2b), 2-cyanoimino-thiazolidine (2c), and (E)-1-methyl-2-nitroguanidine (2d), in a controlled manner, was developed. The hydroamination of α-(trifluoromethyl)styrenes with 2a, 2b, 2c, and 2d was completed in the presence of DBN at room temperature within 0.5–6 h, affording structurally diverse β-trifluoromethyl-β-arylethyl analogues of neonicotinoids in moderate to good yields. The γ,γ-difluoro-β-arylallyl analogues of neonicotinoids were also successfully synthesized via defluorination of α-(trifluoromethyl)styrenes, with 2a and 2c using NaH as base at an elevated temperature together with a prolonged reaction time of 12 h. The method features simple reaction setup, mild reaction conditions, broad substrate scope, high functional group compatibility, and easy scalability.

Styrene remains a major hazard in fiberglass-reinforced plastic (FRP) manufacturing. The current 10 ppm 8-h TLV-TWA is half the former limit, and the movement by several European states toward comparable or lower OELs highlights the need for fresh exposure–response data. In this study, eighty-five Korean FRP workers were monitored cross-sectionally. Full-shift breathing-zone styrene was measured by GC-FID; post-shift urine was analysed for mandelic acid (MA) and phenyl-glyoxylic acid (PGA), and dermal uptake was estimated with fluorescent tracers. Neuro-irritative symptoms were assessed by questionnaire and clinically verified in a subset. The results showed that median styrene levels were 18.65 ppm (spray-up), 12.42 ppm (hand lay-up) and 6.37 ppm (closed-mold). Urinary MA and PGA correlated with air levels (r = 0.78, 0.77). Dermal styrene load showed a moderate correlation with urinary MA (r = 0.42, p < 0.001). Symptom prevalence rose from 19% to 71% across exposure quartiles (adjusted OR = 5.6). A biomarker-based model using urinary mandelic acid (MA) with covariates (age, ventilation) showed strong apparent discrimination (AUC = 0.93). We propose 0.38 mg/g creatinine (MA) as a candidate operational (“early-warning”) threshold, pending external validation. In conclusion, integrated air, biological and dermal metrics reveal dose-dependent acute effects at or below 10 ppm. In this cross-sectional analysis, higher styrene exposure was associated with increased acute symptoms at or below ~10 ppm; these associations warrant confirmation in longitudinal studies with repeated biomonitoring. We present 0.38 mg/g creatinine (MA) as a candidate operational (“early-warning”)threshold to flag workers for closer evaluation; external validation is needed, and engineering controls remain the primary means of risk reduction.

Polymerization reactions conducted inside cells must be compatible with the complex intracellular environment, which contains numerous molecules and functional groups that could potentially prevent or quench polymerization reactions. Here we report a strategy for directly synthesizing unnatural polymers in cells through free radical photopolymerization using a number of biocompatible acrylic and methacrylic monomers. This offers a platform to manipulate, track and control cellular behaviour by the in cellulo generation of macromolecules that have the ability to alter cellular motility, label cells by the generation of fluorescent polymers for long-term tracking studies, as well as generate a variety of nanostructures within cells. It is remarkable that free radical polymerization chemistry can take place within such complex cellular environments. This demonstration opens up a multitude of new possibilities for how chemists can modulate cellular function and behaviour and for understanding cellular behaviour in response to the generation of free radicals. A strategy for directly synthesizing unnatural polymers in cells through radical polymerization has now been developed. This approach provides a platform to manipulate, track and control cellular behaviour by the in cellulo generation of macromolecules and a variety of nanostructures.

2-Phenylethanol (2-PE) is an important flavor ingredient and is widely applied in the fields of food, cosmetics, and pharmaceuticals. Despite that Saccharomyces cerevisiae has the ability to naturally synthesize 2-PE via the Ehrlich pathway, de novo synthesis of 2-PE in high titer still remains a huge challenge. In this study, a non-native styrene degradation pathway was introduced into S. cerevisiae, which represents the first time to demonstrate the functional expression of “styrene-derived” 2-PE synthesis in yeast. Using a host strain engineered with L-phenylalanine (L-Phe) overproduction, the heterologous 2-PE pathway coupled with endogenous Ehrlich pathway produced 233 mg/L 2-PE under shake flasks. Additionally, we further engineered the permease transporters to improve the intracellular L-Phe availability, and further improved the 2-PE titer to 680 mg/L. Taken together, our work represents one of the pioneering reports to explore “styrene-derived” pathway in S. cerevisiae. The synthetic yeast described here might be used as a platform for the future development of next-generation high-yielding 2-PE yeast strains.Key Points• A styrene-derived pathway was established in yeast for 2-phenylethanol productions; membrane-associated styrene oxide isomerase was functional in yeast.• Transporter engineering to improve the L-phenylalanine importation with enhanced 2-phenylethanol productions.

Phase change materials (PCMs) offer great potential for realizing zero-energy thermal management due to superior thermal storage and stable phase-change temperatures. However, liquid leakage and solid rigidity of PCMs are long-standing challenges for PCM-based wearable thermal regulation. Here, we report a facile and cost-effective chemical cross-linking strategy to develop ultraflexible polymer-based phase change composites with a dual 3D crosslinked network of olefin block copolymers (OBC) and styrene-ethylene-butylene-styrene (SEBS) in paraffin wax (PW). The C-C bond-enhanced OBC-SEBS networks synergistically improve the mechanical, thermal, and leakage-proof properties of PW@OBC-SEBS. Notably, the proposed peroxide-initiated chemical cross-linking method overcomes the limitations of conventional physical blending methods and thus can be applicable across diverse polymer matrices. We further demonstrate a portable and flexible PW@OBC-SEBS module that maintains a comfortable temperature range of 39–42 °C for personal thermotherapy. Our work provides a promising route to fabricate scalable polymer-based phase change composite for wearable thermal management. Jing et al. report a cost-effective chemical cross-linking method for synthesizing ultraflexible polymer-based phase change composites with 3D crosslinked networks and further demonstrate portable applications for wearable thermal management.

Amorphous nanomaterials with long-range disordered structures could possess distinct properties and promising applications, especially in catalysis, as compared with their conventional crystalline counterparts. It is imperative to achieve the controlled preparation of amorphous noble metal-based nanomaterials for the exploration of their phase-dependent applications. Here, we report a facile wet-chemical reduction strategy to synthesize various amorphous multimetallic Pd-based nanomaterials, including PdRu, PdRh, and PdRuRh. The phase-dependent catalytic performances of distinct Pd-based nanomaterials towards diverse catalytic applications have been demonstrated. Specifically, the usage of PdRu nanocatalysts with amorphous and crystalline face-centered cubic (fcc) phases can efficiently switch the ring-opening route of styrene oxide to obtain different products with high selectivity through alcoholysis reaction and hydrogenation reaction, respectively. Moreover, when used as an electrocatalyst for hydrogen evolution reaction (HER), the synthesized amorphous PdRh nanocatalyst exhibits low overpotential and high turnover frequency values, outperforming its crystalline fcc counterpart and most of the reported Pd-based HER electrocatalysts.

This work aimed to investigate the effects of aging on the microstructures and rheological properties of modified asphalt with a GO/SBS composite, since the styrene–butadiene–styrene block copolymer is potentially compatible with graphene oxide (GO). The GO/SBS composites, which were used as a kind of modifier, were prepared via the solution-blending method. GO/SBS composites with varying GO contents were employed to prepare the GO/SBS-compound-modified asphalt (GO/SBS-MA). Then, the GO/SBS-MA underwent PAV (pressure aging vessel) or UV (ultraviolet) aging tests to simulate different aging circumstances. The microstructures of the asphalt binders were studied using FTIR (Fourier-transform infrared spectroscopy) and AFM (atomic force microscope) tests. Moreover, DSR (dynamic shear rheometer) and BBR (bending beam rheometer) experiments were carried out to investigate the rheological properties of the GO/SBS-MA. The results showed that the addition of GO improved the high-temperature stability of the asphalt binder while slightly impairing its performance at low temperatures. GO restrained the formation of carbonyl and sulfoxide groups as well as the breakdown of C=C bonds in the polybutadiene (PB) segment, promoting the anti-aging performance of GO/SBS-MA. Furthermore, the interactions between the GO/SBS and the asphalt binder resulted in the formation of needle-like aggregates, enhancing the stability of the asphalt binder. The asphalt binders with a higher content of graphene oxide (GO) exhibited not only a better high-temperature performance, but also a better aging resistance. It was concluded that the macroscopic properties and microstructures were significantly affected by GO, and a moderate increase in the amount of GO could contribute to a better aging resistance for GO/SBS-MA.

The development of fifth‐generation technology has resulted in increased demand for materials with low dielectric losses and superior thermal and mechanical properties. However, ensuring the widespread use of such materials by investigating their aging mechanisms and operating lifetimes remains challenging. In this study, a glass‐fiber (GF)‐reinforced acrylate‐styrene‐acrylonitrile/polycarbonate (ASA/GF/PC) composite is designed and comprehensively investigated its aging behavior, mechanism, and service lifetime under long‐term hygrothermal conditions. Based on the general Peck model, the composite maintains a high level of quality for over 10 years, including under harsh conditions of 40 °C and 80% relative humidity. The aging mechanism is primarily ascribed to cracking between the GF fibers and matrix, the breaking of chemical bonds, the generation of new cross‐linked domains, and physical aging. These findings provide valuable insights into the long‐term utilization of ASA/GF/PC composites in harsh environments. A kind of glass fiber (GF) reinforced acrylate‐styrene‐acrylonitrile/polycarbonate (ASA/GF/PC) composite and comprehensively investigated its aging behavior, mechanism, and service lifetime under long‐term hygrothermal conditions. Assisted by the general Peck model, the composite maintains a high level of quality for over 10 years, even under harsh conditions of 40 °C and 80% relative humidity.

The study focuses on improving the viscosity property of asphalt material by adding a polymeric material which is styrene butadiene styrene a grade of T6302 in different weight percentages with changing the temperature and mixing time. The bitumen was mixed with the polymer by a mixer and by weight ratios of the additive (2, 3, 4, 5 and 6) % at different temperatures (170, 175, 180, 185 and 190) °C and the mixing time (30, 45, 60, 75 and 90) rpm. Taguchi method used to design of the experiments and investigated the best values of these three parameters that effective on viscosity of produced asphalt. Through the tests conducted on the mixture after the mixing process, there was a significant development and improvement in the viscosity of bitumen, which indicates the effect of additives, temperature and mixing process on the quality of the bitumen produced. The obtained results indicated best viscosity for produced bitumen is 2.55 Pa. sec under the following conditions: weight ratio 4-5%, 175 °C and mixing speed 75 minutes.

Although the elastocaloric effect was found in natural rubber as early as 160 years ago, commercial elastocaloric refrigeration based on polymer elastomers has stagnated owing to their deficient elastocaloric effects and large extension ratios. Herein, we demonstrate that polymer elastomers with uniform molecular chain-lengths exhibit enormous elastocaloric effects through reversible conformational changes. An adiabatic temperature change of −15.3 K and an isothermal entropy change of 145 J kg −1 K −1 , obtained from poly(styrene-b-ethylene-co-butylene-b-styrene) near room temperature, exceed those of previously reported elastocaloric polymers. A rotary-motion cooling device is tailored to high-strains characteristics of rubbers, which effectively discharges the cooling energy of polymer elastomers. Our work provides a strategy for the enhancement of elastocaloric effects and could promote the commercialization of solid-state cooling devices based on polymer elastomers. The elastocaloric effect was originally found in natural rubber, but the development of polymer based elastocaloric cooling still remains underdeveloped. Herein, the authors demonstrate that polymer elastomers with uniform molecular chain-lengths exhibit enormous elastocaloric effects through reversible conformational changes.