Showing papers on "Nitrile rubber published in 2020"
TL;DR: In this article, a flexible, biocompatible, nitrile butadiene rubber (NBR)-based strain sensor with high stretchability, good sensitivity, and excellent repeatability is presented for the first time.
Abstract: A flexible, biocompatible, nitrile butadiene rubber (NBR)-based strain sensor with high stretchability, good sensitivity, and excellent repeatability is presented for the first time. Carbon black (CB) particles were embedded into an NBR matrix via a dissolving-coating technique, and the obtained NBR/CB composite was coated with polydopamine (PDA) to preserve the CB layer. The mechanical properties of the NBR films were found to be significantly improved with the addition of CB and PDA, and the produced composite films were noncytotoxic and highly biocompatible. Strain-sensing tests showed that the uncoated CB/NBR films possess a high sensing range (strain of ∼550%) and good sensitivity (gauge factor of 52.2), whereas the PDA/NBR/CB films show a somewhat reduced sensing range (strain of ∼180%) but significantly improved sensitivity (gauge factor of 346). The hysteresis curves obtained from cyclic strain-sensing tests demonstrate the prominent robustness of the sensor material. Three novel equations were developed to accurately describe the uniaxial and cyclic strain-sensing behavior observed for the investigated strain sensors. Gloves and knee/elbow covers were produced from the films, revealing that the signals generated by different finger, elbow, and knee movements are easily distinguishable, thus confirming that the PDA/NBR/CB composite films can be used in a wide range of wearable strain sensor applications.
62 citations
TL;DR: In this article, carbon nanotubes (CNTs) were used as fillers for suppressing their agglomeration and regulating the interfacial interaction between CNTs and carboxylated butadiene nitrile rubber (XNBR) for achieving excellent mechanical properties and better damping properties.
38 citations
TL;DR: In this article, carboxylated nitrile rubber (XNBR) was ionically crosslinked with zinc oxide (ZnO), forming ionic domains grouped into ionic clusters.
37 citations
TL;DR: In this paper, a machine learning framework was developed to predict volume swell for 10 non-metallic materials submerged in neat compounds, including nitrile rubber, polythioether, epoxy, fluorosilicone, fluorocarbon and nylon.
29 citations
26 citations
TL;DR: In this article, the influence of particle size and dispersion on the friction and wear properties of nitrile rubber was investigated, and the results showed that the particle size of SiO2 has a great impact on its dispersion.
22 citations
TL;DR: In this article, the influence of hybrid of multiwalled carbon nanotube and nanoclay on the mechanical, electrical and transport properties of nitrile rubber (NBR)/natural rubber (NR) blends has been investigated.
Abstract: Hybrid fillers are making a remarkable improvement in the properties of polymeric systems. In the present study, the influence of hybrid of multiwalled carbon nanotube (MWCNT) and nanoclay on the mechanical, electrical and transport properties of nitrile rubber (NBR)/natural rubber (NR) blends has been investigated. Attempts were made to prepare NBR/NR/CNT/nanoclay composites on a two-roll mill and to study various mechanical properties such as tensile strength, tear resistance, abrasion loss and compression set percent. Transport, thermal and electrical properties were also investigated. By virtue of the synergism between MWCNT and nanoclay, the composites exhibited enhancement in the mechanical properties by the immobilization of rubber chains via coupling action between the filler surface and the rubber molecules. The fine and uniform dispersion of both CNT and clay in composite samples supported the observation. The hybrid filler system had a great impact on the thermal and electrical properties of the composites.
22 citations
TL;DR: The sustainability of nitrile glove production process is essential both in the financial and energy perspective, and blending of bio-additive into the Nitrile latex might support the 3 pillars of sustainability for environmental, societal, and financial sector.
Abstract: The sustainability of nitrile glove production process is essential both in the financial and energy perspective. Nitrile glove has the lowest material cost with positive mechanical and chemical performance quality for the disposable glove market. Nitrile glove also holds a major market in disposable gloves sector, and nitrile rubber compounds may contribute to the huge reduction of the capital cost for a pair of surgical gloves due to the inexpensive raw material compares with other synthetic polyisoprene or neoprene. Hence, blending of bio-additive into the nitrile latex might support the 3 pillars of sustainability for environmental, societal, and financial sector. Bio-additives helps increase the degradation rate of gloves under natural conditions. Bio-based substances could be derived from food waste, natural plants, and aquatic plants like micro- and macro algae. Furthermore, antimicrobial agent (e.g. brilliant green and cyclohexadiene) is the trend in surgical glove for coated as protecting layer, due to the capability to remove pathogens or bacterial on the surgeon hands during operation period. Besides, the section in energy recovery is a proposing gateway for reducing the financial cost and makes the process sustainable.
19 citations
TL;DR: In this paper, the authors presented the development and thermal and mechanical considerations of sensing elements using different diaphragm materials which are embedded in optical fiber Bragg gratings (FBGs).
Abstract: This letter presents the development and thermal and mechanical considerations of sensing elements using different diaphragm materials which are embedded in optical fiber Bragg gratings (FBGs). Diaphragms made of polyurethane, polydimethylsiloxane (PDMS) and nitrile rubber were fabricated, and all of them with embedded FBGs. Tensile tests were performed in each material, showing the lower Young’s modulus of the PDMS (0.8 MPa), which is orders of magnitude lower than the ones of polyurethane (2.0 MPa) and nitrile rubber (362.2 MPa). Moreover, the highest strain limit was obtained in the PDMS diaphragm (24.5%). These results indicated the potential for higher pressure sensitivity of the PDMS, which was confirmed in the pressure characterization tests (pressure sensitivity of 1.4 nm/kPa). In addition, temperature tests indicated a higher sensitivity of the nitrile rubber, which presented a sensitivity of 49.8 pm/°C. Considering applications in which there are simultaneous variation of pressure and temperature, the nitrile presented a cross-sensitivity of 0.01 nm kPa−1°C−1 which is the lowest among the materials tested, indicating the possibility of obtaining the mitigation of temperature influence in the pressure response. It is also worth noting that the highest measurement range was obtained in the nitrile rubber diaphragm with linear responses in the range of pressures up to 3 kPa.
17 citations
TL;DR: In this article, the authors investigated the properties of three short rockwool fibers/nitrile rubber composites with different length and modification and concluded that the fiber with chemical modification had better interfacial interaction with the polymer enhancing modulus at 100% deformation, Shore A hardness, tear strength, Payne effect and stress relaxation under a compressive regime.
17 citations
TL;DR: This work provides a novel strategy to fabricate the sustainable elastomers with minimum environmental impact by copolymerizing bis(6-membered cyclic carbonate) and amino-terminated liquid nitrile rubber and tuning the monomer feeding ratio.
Abstract: Developing degradable and self-healable elastomers composed of reusable resources is of great value, but is rarely reported due to the undegradable molecular chains. Herein, we report a class of degradable and self-healable vitrimers based on non-isocyanate polyurethane elastomer. Such vitrimers are fabricated by copolymerizing bis(6-membered cyclic carbonate) and amino-terminated liquid nitrile rubber (ATBN). The networks topologies can rearrange by transcarbonation exchange reactions between hydroxyl and carbonate groups at elevated temperatures; as such vitrimers after reprocessing can recover 82.9-95.6 % of initial tensile strength and 59−131 % of initial storage modulus. Interestingly, the networks can be hydrolyzed and decarbonated in the strong acid solution to recover 75 % of the pure di(trimethylolpropane) monomer. Additionally, the elastomer exhibits excellent self-healing efficiency (~88 %) and fracture strain (~1200 %) by tuning the monomer feeding ratio. Therefore, this work provides a novel strategy to fabricate the sustainable elastomers with minimum environmental impact.
TL;DR: This paper presents a conceptually different synthesis pathway for functional carbon materials based on hypergolic mixtures, i.e., mixtures that spontaneously ignite at ambient conditions once its ingredients contact each other, and demonstrates that the energy released from thesehypergolic reactions can serve as a heat source for the thermal conversion of certain triazine-based precursors into graphitic carbon nitride.
Abstract: Carbon formation from organic precursors is an energy-consuming process that often requires the heating of a precursor in an oven at elevated temperature. In this paper, we present a conceptually different synthesis pathway for functional carbon materials based on hypergolic mixtures, i.e., mixtures that spontaneously ignite at ambient conditions once its ingredients contact each other. The reactions involved in such mixtures are highly exothermic, giving-off sizeable amounts of energy; hence, no any external heat source is required for carbonization, thus making the whole process more energy-liberating than energy-consuming. The hypergolic mixtures described here contain a combustible organic solid, such as nitrile rubber or a hydrazide derivative, and fuming nitric acid (100% HNO3) as a strong oxidizer. In the case of the nitrile rubber, carbon nanosheets are obtained, whereas in the case of the hydrazide derivative, photoluminescent carbon dots are formed. We also demonstrate that the energy released from these hypergolic reactions can serve as a heat source for the thermal conversion of certain triazine-based precursors into graphitic carbon nitride. Finally, certain aspects of the derived functional carbons in waste removal are also discussed.
TL;DR: In this paper, a catalyst-free and recycle-reinforcing elastomer vitrimer was revealed by the reactive blending of commercially available epoxidized natural rubber and carboxylated nitrile rubber.
Abstract: Vitrimers, as intriguing polymers, possess exchangeable links in the crosslinking networks, endowing them with the abilities of recycling and reprocessing. However, most of vitrimers are generally fabricated via complex synthesis and polymerization processes. Toxic and unstable exogenous catalysts are inevitably applied to activate the exchange reaction to rearrange the crosslinking networks. These drawbacks limit the widespread applications of vitrimers. Moreover, most reported vitrimers could only partially maintain or severely deteriorate their mechanical properties after recycling. Herein, to solve the above-mentioned problems, for the first time, a catalyst-free and recycle-reinforcing elastomer vitrimer is revealed. By the reactive blending of commercially available epoxidized natural rubber and carboxylated nitrile rubber, the elastomer vitrimer associated with exchangeable β-hydroxyl ester bonds was obtained. Strikingly, the vitrimer exhibits an exceptional recycle-reinforcing property. This work provides a feasible method to fabricate elastomer vitrimers, which promotes the recycling of crosslinking commercial available elastomers.
TL;DR: In this paper, greener rubber nanocomposites exhibiting high crosslinking density, and excellent mechanical and thermal properties, with a potential application in technical fields including high-strength and heat-resistance products are designed.
Abstract: In this paper we designed greener rubber nanocomposites exhibiting high crosslinking density, and excellent mechanical and thermal properties, with a potential application in technical fields including high-strength and heat-resistance products. Herein 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) ionic liquid was combined with silane coupling agent to formulate the nanocomposites. The impact of [EMIM]OAc on silica dispersion in a nitrile rubber (NBR) matrix was investigated by a transmission electron microscope and scanning electron microscopy. The combined use of the ionic liquid and silane in an NBR/silica system facilitates the homogeneous dispersion of the silica volume fraction (φ) from 0.041 to 0.177 and enhances crosslinking density of the matrix up to three-fold in comparison with neat NBR, and also it is beneficial for solving the risks of alcohol emission and ignition during the rubber manufacturing. The introduction of ionic liquid greatly improves the mechanical strength (9.7 MPa) with respect to neat NBR vulcanizate, especially at high temperatures e.g., 100 °C. Furthermore, it impacts on rheological behaviors of the nanocomposites and tends to reduce energy dissipation for the vulcanizates under large amplitude dynamic shear deformation.
03 Apr 2020
TL;DR: Analysis of the results reveals that in situ zirconia could be an excellent filler for the NBR composites to withstand in a harsh and adverse environment.
Abstract: Zirconia particles are generated into a nitrile rubber (NBR) matrix via a solution sol-gel method in a controlled manner. Formation of zirconia particles from their precursor (zirconium(IV) propoxide) occurs under optimized reaction conditions. As a result, the nanoparticles are embedded and well dispersed in the NBR matrix that results in a remarkable improvement in mechanical and thermal properties of the composite. Such reinforcement is not realized when the composites are prepared following the conventional technique of filler loading by physical mixing, although the filler content remains the same. Use of a surface active coupling agent TESPT (bis-(3-triethoxysilylpropyl) tetrasulfide) in the reactive sol-gel system is found to further boost the mechanical performance of the composites. In order to ensure the practical application of the developed composites, a series of studies have been performed that consist of dynamic performance, swelling, thermal degradation, and resistance to oil, ozone, and abrasion. Analysis of the results reveals that in situ zirconia could be an excellent filler for the NBR composites to withstand in a harsh and adverse environment.
TL;DR: The permeability of the systems was correlated with blend morphology and dispersion of the nanoclay platelets in the polymer blend, and it was found that the permeability decreased with the incorporation ofnanoclay.
Abstract: In this paper, gas permeability studies were performed on materials based on natural rubber/acrylonitrile butadiene rubber blends and nanoclay incorporated blend systems. The properties of natural rubber (NR)/nitrile rubber (NBR)/nanoclay nanocomposites, with a particular focus on gas permeability, are presented. The measurements of the barrier properties were assessed using two different gases—O2 and CO2—by taking in account the blend composition, the filler loading and the nature of the gas molecules. The obtained data showed that the permeability of gas transport was strongly affected by: (i) the blend composition—it was observed that the increase in acrylonitrile butadiene rubber component considerably decreased the permeability; (ii) the nature of the gas—the permeation of CO2 was higher than O2; (iii) the nanoclay loading—it was found that the permeability decreased with the incorporation of nanoclay. The localization of nanoclay in the blend system also played a major role in determining the gas permeability. The permeability of the systems was correlated with blend morphology and dispersion of the nanoclay platelets in the polymer blend.
TL;DR: Both the dispersion of the CNF in the NBR matrix and the polymer-filler interactions were improved following silane modification, as shown in SEM images and by the Payne Effect.
Abstract: Two different silane treatment methods were used to improve the reinforcing activity of carbon nanofibers (CNF) in acrylonitrile-butadiene rubber (NBR) composites. The first method was chemical silanization with [3-(2-aminoethylamino)propyl]trimethoxysilane (APTS) in ethanol solution, preceded by oxidation of the CNF with H2SO4/HNO3. The second method was direct incorporation of silanes during preparation of the composites (in-situ silanization). Three different silane coupling agents were used: [3-(2-aminoethylamino)propyl]trimethoxysilane, (3-mercaptopropyl)trimethoxysilane (MPTS), and 3-ureidopropyltrimethoxysilane (UPTS). The NBR composites were prepared in an internal laboratory mixer, with increasing concentrations of pure or modified CNF. The crosslink density and flammability of the NBR-filled composites were analyzed, as well as their rheological and mechanical properties. The electrical conductivity of the composites was measured to assess the formation of CNF networks in the elastomer matrix. The morphology of the CNF was assessed by scanning electron microscopy (SEM). Both the dispersion of the CNF in the NBR matrix and the polymer-filler interactions were improved following silane modification, as shown in SEM images and by the Payne Effect. The composites were also found to have enhanced moduli, tensile strength, hardness, damping, and electrical conductivity. Chemical treatment proved to be more effective at improving the reinforcing effect of CNF in the elastomer matrix than in-situ silanization. The results of this study demonstrate the great potential of both in-situ and chemical silanization for the preparation of reinforced polymer composites filled with CNF.
TL;DR: In this article, the formation of blend nanocomposite was analyzed by FTIR, XRD, TEM, SEM, and TGA with different contents of nano-hydroxyapatite (HA).
Abstract: Novel elastomeric blend nanocomposites of chlorinated nitrile rubber (Cl-NBR) and chlorinated ethylene-propylene-diene rubber (Cl-EPDM) with different contents of nano-hydroxyapatite (HA) were prepared The formation of blend nanocomposite was analyzed by FTIR, XRD, TEM, SEM and TGA The fire resistance, dielectric behavior and diffusion of petroleum fuels through the blend membrane had been investigated as a function of nanoparticle loading The FTIR revealed the absorption band of HA in the rubber blend indicated the effective interaction between HA nanofiller and the rubber blend XRD plots indicated a reduction in amorphous region of rubber blend with the addition of nanoparticles TEM and SEM images revealed the uniform dispersion of nanoparticles in the rubber blend TGA results indicated that the thermal stability of rubber blend nanocomposite was higher than Cl-NBR/Cl-EPDM blend Increased fire resistance of blend composites obtained from limiting oxygen index demonstrated that hydroxyapatite nanoparticles were served as an excellent fire-retardant additive for Cl-NBR/Cl-EPDM blend Improvement in dielectric constant with the loading of nanoparticles indicated the reinforcement of blend matrix by the HA nanoparticles The solvent uptake of blend nanocomposite decreased up to 7 phr HA-loaded sample A decrease in solvent uptake was also observed with the increase in molecular size of the penetrant molecules The mechanism of diffusion was anomalous in nature Overall, the sample with 7 phr of HA-filled rubber blend showed a remarkable increase in dielectric properties, flame resistant and minimum solvent uptake
TL;DR: The aim of the research was to evaluate the friction reducing capability of graphite in rubbers of commercial sealing parts and found that in the case of the two tested materials, the addition ofgraphite powder had an influence on the decrease in the friction force.
Abstract: This paper presents the outcome of the measurement of the tribological characteristic of O-ring seals in the event of operating in conditions with a lack of lubrication. The measurement was carried out on a seal and rod model. The measurement was carried out during the condition of the round cross-section seal sliding on the surface of the piston rod. We analyzed how the friction force during rod movement, which resulted from the cooperation of the sliding nod and the rod, was changing. The experiment was conducted for various rubber materials. The aim of the research was to evaluate the friction reducing capability of graphite in rubbers of commercial sealing parts. Typical materials used for the seal and the materials, which contained the filler in the form of graphite powder, were compared. Synthetic graphite powder with a particle size of 1-2 µm was applied, and nitrile rubber (NBR) and fluoroelastomer (FKM) were compared as typical materials for O-ring seals. In the case of the two tested materials, the addition of graphite powder had an influence on the decrease in the friction force.
TL;DR: In this paper, the effect of hydroxyapatite nanoparticles (HA) on the cure characteristics, tensile and tear strength, elongation at break, hardness, abrasion resistance, heat build-up, resilience, glass transition temperature, oil resistance, alternating current (AC) conductivity and transport properties of chlorinated nitrile rubber (Cl-NBR).
TL;DR: In this article, the effect of the blend ratio on processing characteristics, mechanical properties (such as tensile and tear strength, elongation at break, hardness, abrasion resistance, heat build-up and resilience), structure, morphology, glass transition temperature (Tg), thermal stability, flame retardancy, oil resistance, AC conductivity, dielectric properties and transport behavior of petrol, diesel and kerosene were investigated.
13 Oct 2020
TL;DR: In this paper, the authors proposed substituting flammable liquid electrolytes with solid polymer electrolytes (SPEs) presents a serious challenge in improving the safety of lithium-ion batteries.
Abstract: Substituting flammable liquid electrolytes with solid polymer electrolytes (SPEs) presents a serious challenge in improving the safety of lithium-ion batteries. Even though SPEs are a safer choice,...
TL;DR: In this article, the effect of anti-aging agents on the magnetic composites was explored and the authors provided constructive suggestions to further modify and select the antioxidants for the magnetic composite.
TL;DR: The studies manifested that EACO and EBCO can replace DOP to plasticize NBR and are used in fields that require high mechanical properties, aging resistance, and thermal stability.
Abstract: A series of new environment-friendly plasticizers was synthesized from castor oil and used to plasticize nitrile rubber (NBR). The test results showed that tensile strength, elongation at break, and tear strength of NBR vulcanizates plasticized by castor oil-based plasticizers were found to be better than that of dioctyl phthalate (DOP). The aging test taken demonstrated that the castor oil-based plasticizers could improve the hot air and oil aging resistance of NBR vulcanizates. The thermal stability test illustrated that castor oil-based plasticizers enhanced the thermal stability of NBR vulcanizates, and the initial decomposition temperatures (T10%) were about 100 °C higher than that of DOP. In general, the studies manifested that EACO and EBCO can replace DOP to plasticize NBR and are used in fields that require high mechanical properties, aging resistance, and thermal stability. This study emphasizes the effects of sustainable, cost-effective, and high-efficiency plasticizers on NBR.
TL;DR: Powdered nitrile rubber@ silicon dioxide (PNBR@SiO2) capsules were successfully prepared based on the sol-gel method and introduced into phenolic resin composites (PRC) as wear modifiers.
TL;DR: In this paper, the authors investigated the ablation behavior of rubber-based insulators containing silica and silica-clay aerogels in comparison with those containing fumed silica, and found that silica aerogel played more effective role in reduction of the back-face temperature of insulators.
Abstract: Nitrile-based nanocomposite heat insulators are very attractive materials, due to their higher deformation bearing in special applications such as high temperature and turbulent media, compared to their non-elastomeric counterparts. Ablation behavior of nitrile rubber-based insulators containing silica and silica-clay aerogels was investigated in comparison with those containing fumed silica. An oxyacetylene flame test under a standard condition with a heat flux of 2500 kW m−2 for 15 s was used for observation of ablation behavior of the samples. The results showed that the incorporation of 15 phr (part per hundred parts of rubber) silica aerogel into the compound decreased the mass of insulator and its linear ablation rate by 15% and 29%, respectively. The incorporation of 5 wt% organoclay in silica aerogel successfully reduced the linear ablation rate to nearly 41%. The results indicated that the insulation index number (I80) of the insulators increased about 29% and 20%, at this loading levels of silica and silica-clay aerogels, respectively. Therefore, silica aerogel played more effective role in reduction of the back-face temperature of insulators. Modeling of these ablative nanocomposites enables us to determine the exact thickness required for the insulator and the temperature distribution across it at pre-determined thermal conditions. The experimental results confirmed modeling results of the back-face temperature of the insulators.
TL;DR: In this article, a polyvinylidene fluoride (PVDF)/hydrogenated nitrile rubber (HNBR)-based flexible electroactive polymer blend was developed by generating a suitable morphology that showed a judicious combination of strength and flexibility.
Abstract: A polyvinylidene fluoride (PVDF)/hydrogenated nitrile rubber (HNBR)-based flexible electroactive polymer blend was developed by generating a suitable morphology that showed a judicious combination of strength and flexibility. The blend, containing 30:70 wt/wt ratio of PVDF/HNBR, was thermoplastic elastomeric in nature and exhibited visible planar actuation in the presence of an electric field. To the best of our knowledge, the electromechanical actuation of the thermoplastic elastomeric blend has been reported for the first time. The maximum planar strain was 5%, and the actuation was triggered by the strong induced polarization in both PVDF and HNBR phases that gave rise to a high dielectric constant and low dielectric losses. The interphase between PVDF and HNBR was also very strong, which made the thermoplastic elastomer (TPE) susceptible to withstand high electric field. The TPE also exhibited a bending actuation of 0.6 mm at a low electric field of 20 kV/mm, promising enough to be used in microdevices. Addition of barium titanate (BT) nanoparticles increased the dielectric constant as they were homogeneously distributed in both the phases. The maximum planar actuation (∼10%) was observed at 10 wt % BT loading, whereas 5 wt % loading exhibited the maximum dielectric strength (∼120 kV/mm). At 5 wt % loading, the bending actuation was 0.9 mm at 20 kV/mm, which was 50% higher than that of unfilled TPE. Both the TPE and its nanocomposite also showed good history dependency in a cyclic electric field. In summary, the study provides an attractive and unexplored alternative of developing electromechanically active TPEs and their nanocomposites.