Low-Speed near-space aerostats (e.g., stratospheric airships and high-altitude balloons) are low-speed unmanned aerial vehicles (UAVs) extensively utilized in communication coverage, remote sensing applications, environmental monitoring, aviation support, and other fields. A paramount challenge constraining their precise and stable operation is the leakage of buoyant gas, such as helium (He), in the harsh and unpredictable near-space environment. One of the primary causes of gas leakage is the degradation of their dedicated sealing rings. This study aims to clarify the aging mechanisms of high-performance rubber seals in near-space environments and establish a reliable service life prediction model to address the gas leakage risk of unmanned platforms. Two widely used high-performance rubber materials—ethylene propylene diene monomer (EPDM) and chloroprene rubber (CR)—were subjected to accelerated aging experiments under simulated near-space environment conditions. Their degradation was then quantified through performance degradation characterization, covering mass loss, hardness, elastic deformation, and tensile strength. A predictive model was established to estimate the mass loss rates and service life of the seals. The model revealed that EPDM exhibits superior performance to CR under near-space conditions: the aging behavior is strongly dependent on material composition, thickness, and preload, while being independent of outer diameter. Results show EPDM seals have a near-space service life of 300 days (50% longer than CR’s 200 days), with aging dependent on material composition, thickness (2 mm seals degrade 110% slower than 0.5 mm ones), and preload, but independent of outer diameter. These results provide actionable design guidelines for optimizing seal materials and geometries in aerostat pressure systems, thereby advancing the development of innovative low-speed UAV technologies and the successful application of these technologies in the emerging near-space field. These findings and the proposed methodology are directly applicable to sealing system optimization for various near-space unmanned platforms (e.g., stratospheric UAVs, high-altitude autonomous balloons), enhancing their long-duration operational reliability and mission success rate in extreme environments.

Olefin metathesis-driven deconstruction and upcycling of chloroprene rubber

Contact allergy to benzisothiazolinone (BIT) has increased in recent years, but exposure to it is not always found. It's important to know whether the gloves might be an isothiazolinone source especially in patients with symptoms from gloves and isothiazolinone contact allergy with or without allergy to rubber chemicals. To present results of chemical analysis of isothiazolinones in disposable rubber gloves of patients in an occupational dermatology clinic. We went through our chemical analysis record from 2018-2025 and identified isothiazolinone analyses done from disposable rubber gloves. The chemical analysis of glove extracts was done by liquid chromatography-mass spectrometry (LC-MS). We screened the respective patients' files and collected information on their occupation, glove usage, patch test reactions as well as basic information on their hand eczema. We discovered BIT in 30/54 (60%) analysed gloves (27 nitrile rubber gloves, 2 neoprene rubber gloves and 1 natural rubber glove) in concentrations of 0.3-73.7 ppm (mean 12.7 ppm, median 4.2 ppm). Methylisothiazolinone (MI) was found in solitary gloves in small concentrations. Isothiazolinone-containing gloves were samples from altogether 21 patients, and six of them had several gloves that contained isothiazolinones. Many patients had also other isothiazolinone sources at work or at home. Disposable rubber gloves are a possible BIT source. Several gloves contained BIT in a concentration that may be enough to induce contact allergy when gloves are used frequently.

The reliability of rubber materials in nuclear sealing applications depends on their resistance to ionizing radiation. To explicitly reveal the differences in radiation damage mechanisms among rubbers with varying molecular structures, this study investigated four typical elastomers—natural rubber (NR), butyl rubber (IIR), chloroprene rubber (CR), and nitrile rubber (NBR)—under 60Co γ-irradiation at cumulative doses of 1, 10, and 100 kGy. By coupling macroscopic physical testing (mechanical, permeability) with microstructural characterization (FT-IR, DSC, crosslink density), a correlation between material structure and irradiation behavior was established. The results indicate that main-chain saturation dictates the dominant degradation mechanism: unsaturated rubbers (NR, CR, NBR) are dominated by cross-linking, macroscopically manifested as increased hardness and reduced ductility; conversely, saturated rubber (IIR) is dominated by main-chain scission, leading to a paste-like transition at 100 kGy and a complete loss of mechanical load-bearing and barrier functions. Comparatively, NR exhibited optimal overall stability due to “clean” cross-linking without significant oxidation. The overall radiation resistance ranking within the 0–100 kGy range is NR > CR > NBR > IIR. This study clarifies the “structure-mechanism-property” evolution law, providing a critical theoretical basis for lifetime prediction and rational material selection of rubber components in nuclear environments.

This work aimed to investigate the properties of cross-linked elastomeric blends based on natural rubber (NR) and chloroprene rubber (CR), incorporating plant-derived fillers as environmentally friendly additives. The selected eco-friendly biofillers included ginseng, lemongrass, turmeric, or wood flour. In situ surface modification with n-octadecyltrimethoxysilane was carried out to enhance the compatibility between the fillers and the elastomeric matrix. The results showed that both unmodified and silane-modified plant-based fillers can be effectively used in NR/CR composites, yielding vulcanizates with favorable performance characteristics. The ginseng-filled composite exhibited the highest degree of cross-linking and superior mechanical strength among the tested materials. Turmeric, in both its unmodified and silane-treated forms, contributed to the greatest resistance against aging factors. Notably, the silane-modified wood flour filler significantly improved tear resistance, nearly doubling that of the unfilled rubber. Overall, these novel rubber composites demonstrate not only promising functional properties but also considerable ecological and economic advantages.

ABSTRACT The longevity performance of rubber composites used in harsh environmental conditions can be ensured by their molecular transport kinetic behavior through swelling studies. In this study, systematic investigations are carried out on the solvent transport behaviors of novel ternary elastomeric composites comprising varied content of nitrile‐butadiene rubber (NBR), chloroprene rubber (CR), and epoxidized natural rubber (ENR) with a constant 30 phr CB loading. The compatibility of mixing is ensured through their almost equal solubility parameter values. The elastomeric contents of the ternary composites are decided following a simplex centroid mixture design approach of Design of Experiments (DoE). In order to study the effect of curing systems, seven composites were prepared and cured by sulfur and another seven by peroxide curing. Solvent transport behaviors of these developed composites are characterized through swelling experiments carried out at room temperature 27°C using different solvents. By adopting standard empirical and Fickian diffusion models, the baseline parameters such as diffusion, sorption, and permeability coefficients are obtained. The results highlighted that sulfur cured systems swell higher due to less dense and flexible polysulphidic crosslinks, whereas those of peroxide cured systems swell lesser due to high density and rigid radical crosslinks. Furthermore, 10 phr ENR content provides better homogenization of the blend and also offers effective swelling and diffusion resistance to the composite. In kinetic model studies, the best fit is obtained for the Pepas–Sahlin model, which ensures that in all the composites, the transport of solvents is governed mainly by the diffusion‐driven phenomena.

In this study, we demonstrated chloroprene rubber (CR)-based composites with the addition of synthesized alumina nanofibers (AONF) with a high aspect ratio (>1000). AONF were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). AONF were introduced by pre-dispersion. The resulting chloroprene rubber/aluminum oxide nanofiber (CR/AONF) composites were subjected to tensile and shear adhesive bonding tests. The tensile test results for the CR/AONF composites are 81% greater than those of the original CR composite (0.85 MPa and 1.54 MPa, respectively). Shear adhesive bonding tests were conducted for glass and steel. CR/AONF demonstrates a 213% (for steel) and 262% (for glass) increase in shear strength. The main strengthening mechanisms are reinforcement, CR adsorption on the AONF surface, and crack arrest. These results may expand our understanding of the potential of sealant strengthening using AONF.

This study evaluated the dynamic behavior of a landing gear system made from composite materials. The composite material used is a combination of epoxy resin reinforced with carbon fiber, with an elastomeric layer made from neoprene rubber sandwiched between them. Four different configurations of the elastomer layer were investigated through simulation. The results showed that incorporating elastomeric material in both the inner and outer layers of the landing gear reduces stiffness but increases the damping ratio of the system. The simulations, which employed both linear and bilinear spring models, were conducted to assess the impact of adding the elastomeric layer on the vibration response. It was observed that the vibration amplitudes in the system modelled with the bilinear spring were lower than those in the system modelled with the linear spring.

High-efficiency, ultra-flexible organic solar cells enabled by chloroprene rubber as both a non-volatile solid additive and plasticizer

This paper aimed to evaluate the effect of cross-linking temperature on the rheological, mechanical, and thermal properties of CR/BR compositions cross-linked with zinc oxide, iron(III) oxide, or copper(II) oxide. Properties of CR/BR compounds were studied at four temperatures: 140, 160, 180, and 200 °C. The lowest activation energy of vulcanization was shown by blends cross-linked with ZnO, and the highest activation energy of vulcanization was shown by samples with Fe2O3. Blends cured with ZnO or Fe2O3 showed higher cross-linking activity than CuO. Higher temperatures enhanced the degree of cross-linking in the CR/BR composite cured with ZnO or CuO but slightly reduced it for the CR/BR/Fe2O3 vulcanizates. The highest tensile strength was observed for the CR/BR/Fe2O3 product. However, compositions cured with ZnO exhibited the best aging resistance. The CR/BR compounds cured with ZnO at high temperatures had the highest tear strength (16.8 N/mm), while samples containing CuO as a curing agent showed declining tear strength with temperature. DSC confirmed a single glass transition (~36 °C), indicating good elastomers dispersion. Infrared and SEM analyses confirmed effective cross-linking and blend compatibility.

The transmission of vibrations generated by high-powered machines to the hands can lead to serious health problems and various work-related difficulties for the operators. These issues result in a loss of workforce and increased operational costs due to compensation payments made to affected workers. Exposure to hand–arm vibration can be controlled through the use of vibration damping gloves. In this study, the hand–arm vibration exposure of operators using a jackhammer in three different mines was measured with and without gloves, and the vibration damping ratio of each glove was calculated. One-way analysis of variance was performed to determine the difference between the vibration damping ratios (%) obtained from three separate field measurements of 12 different gloves, and significant differences were detected. In addition, vibration exposure was measured with and without gloves for operators using a vibrating sieve set with standard vibration in a laboratory environment. From both the field and laboratory measurements, the gloves made of chloroprene rubber provide the most effective protection.

Enhancing Oxygen Barrier and γ-Ray Shielding Properties of Neoprene Rubber by Bismuth-Loaded Alkyne-Graphene

The Influence of Various Resins on Adhesive Strength of Chloroprene Rubber Adhesive Compositions

The molecular simulation is an effective approach for investigating the effects of energetic ion irradiation on polymers. However, there is a lack of relevant studies on atomic structural changes and quantitative analysis. This study utilizes an inelastic thermal spike model and reactive molecular dynamics simulations to investigate the damage mechanisms of noble gas ion irradiation in neoprene rubber. The ion track structure and chemical damage mechanism are systematically studied. The radiolytic products are observed to form a distinctive core-shell structure with a threshold in electronic energy loss (Se). Subtle chemical structural changes are noted in the track shell, in stark contrast to the pronounced damage observed in the track core. Additionally, the four distinct types of repeating units in the neoprene molecular chain are found to significantly influence both the structure and the yield of the radiolytic products. The extent of chemical damage is further quantitatively analyzed. A remarkable linear relationship is verified between damage cross sections (σ) and Se. Moreover, the activation energy associated with the same chemical structure is found to remain constant. These results are in alignment with previous experimental studies. This work provides an effective and accurate simulation method for studying radiolytic mechanisms in polymers.

This study investigates the impact of ozone exposure on the hardness of synthetic rubber specimens (a blend of NR (natural rubber) and CR (chloroprene rubber)) through accelerated aging tests. Using a linear regression model, the research predicts the lifespan of rubber under real-world conditions and demonstrates how established experimental methods can yield novel insights when applied to synthetic rubber. The results show that ozone exposure significantly increases hardness within the first 10 days, stabilizing after day 12. Through analysis, this study calculates acceleration factors based on ozone concentration and temperature, estimating the practical lifespan of synthetic rubber under actual conditions to be approximately 25.76 years. These findings provide valuable indicators for evaluating the durability of synthetic rubber materials and predicting the longevity of rubber products in industrial applications. Furthermore, the research emphasizes the potential for improving lifespan prediction accuracy by incorporating non-linear models or machine learning approaches.

Supercritical N2-induced lightweight high-strength chloroprene rubber foam with excellent flame-retardant and smoke suppression

Fatigue is a phenomenon that occurs in materials when they are subjected to repetitive or cyclic loading, which can lead to the accumulation of damage over a time. The purpose of the present study is to develop a fatigue damage model incorporating experimental test results of axial tension and fatigue that utilizes the principles of continuum damage mechanics (CDM) to predict the damage accumulation in composite. Experimental testing in axial tensile tests involves dumbbell specimens of neoprene rubber sandwiched with bi-directional carbon fabric to constitute a composite material with the help of which material constants C10, C20, and C30 parameters are evaluated by the curve-fitting method. Fatigue tests were conducted for different displacements, from which constants s0 and S0 were figured out using a linear regression method. A mathematical model is developed, and MATLAB is used to relate stress and strain in Yeoh’s strain energy function to describe the nonlinear elastic behavior of elastomers incorporating material parameters evaluated by axial tensile tests and fatigue tests. The MATLAB script was run in ANSYS with this modified Yeoh hyperelastic model for evaluation of damage in composite and compared with damage evaluated by image processing software in scanning electron microscope (SEM) images for validation purposes.

ABSTRACTNovel shape memory thermoplastic vulcanizates (TPVs) based on polylactic acid (PLA) and chloroprene rubber (CR) have been fabricated via a dicumyl peroxide (DCP)‐induced dynamic vulcanization process. In situ, melt reactive compatibilization was achieved by molecular grafting of PLA onto the CR chains. This was evidenced by ATR‐FT‐IR spectroscopy, swelling test, and dynamic mechanical thermal analysis (DMTA) results. Field emission scanning electron microscopy revealed co‐continuous morphology for dynamically vulcanized PLA/CR blends even at a 70/30 phase ratio of PLA/CR compared to the unvulcanized counterpart samples. This novel microstructure surprisingly indicated a network with excellent shape memory performance with shape fixity close to 100% and high shape recovery of ~90% compared to pure PLA. Furthermore, the PLA/CR thermoplastic vulcanizate (TPVs) displayed significantly improved tensile and impact strength in comparison with the unvulcanized PLA/CR blends, which are attributed to both the microstructure of the blend and the chemically cross‐linked nature of PLA and CR chains. The DMTA results illustrated higher elastic modulus for TPVs as a result of dynamic vulcanization and their unique microstructure.

This study aimed to investigate the properties of tin(II) oxide (SnO) as an unconventional cross-linking agent for chloroprene (CR) and styrene-butadiene (SBR) rubbers compositions. The use of tin(II) oxide results from the need to reduce the use of zinc oxide as a cross-linking agent due to environmental regulations and its toxic impact on aquatic environments. The studied elastomeric blends can be cross-linked with tin(II) oxide, and the results demonstrate the significant potential of this oxide in such applications. The CR/SBR vulcanizates cross-linked with SnO exhibit good mechanical properties and a high degree of cross-linking. The studies clearly show that the proportions of both rubbers as well as the amount of tin(II) oxide used influence the cross-linking of the CR/SBR blends and the properties of vulcanizates. FTIR spectrum analysis allowed the identification of the cross-linking mechanism, which followed the Friedel-Crafts alkylation reaction mechanism. The AFM analysis determined the miscibility of the rubbers and interelastomeric reactions, proving that the rubbers studied are partially miscible. The results of the oxygen index measurements indicated that the obtained vulcanizates showed flame resistance and self-extinguishing properties. Multivariate regression was performed to fit the models to the experimental value and to determine the influence of the content of the cross-linking agent and the CR and SBR proportions on the properties of the blends.

Abstract In the ever-evolving automotive industry, the enhancement of vehicle performance hinges on fundamental components, with the rubber bush in vehicle suspension emerging as a critical element for transformative innovation. This research delves into the optimization of rubber bushes through vulcanization, a process renowned for augmenting rubber’s mechanical properties. The study scrutinizes the performance characteristics of various rubber materials, evaluating their suitability for incorporation into suspension rubber bushes. The research employs a rigorous three- stage testing methodology, including compression, tensile, and fatigue tests, utilizing a Universal Testing Machine (UTM). These stages provide comprehensive insights into the materials’ responses to compression forces, tensile strengths and weaknesses, and fatigue resistance. The findings aid in the informed selection of materials for suspension rubber bushes, contributing to the advancement of automotive suspension system technology. This study not only enhances our understanding of rubber material behaviour but also offers practical insights for applications in automotive engineering. Aligned with the goal of advancing suspension system technology, the research underscores the importance of material-specific properties in real-world scenarios. Ultimately, this research is poised to make a significant contribution to the continual evolution of automotive suspension systems, emphasizing durability, resilience, and overall performance. Neoprene rubber exhibits performance qualities in compression, tensile strength, and fatigue resistance that are equivalent to those of natural rubber, according to the extensive testing findings. This implies that neoprene rubber is a good substitute for using in suspension bushings, providing manufacturers and vehicle engineers with a tempting choice.