Nitrile Butadiene Rubber Composites Research Articles

Application of DPG/KH550 modified pyrolysis carbon black in oil and high temperature‐resistant NBR composites

AbstractIn this paper, pyrolysis carbon black (CBp) was introduced into nitrile butadiene rubber (NBR), the effects of the ratio of CBp and carbon black (N326) on the properties of NBR composites were investigated, and the optimal ratio was determined. On this basis, the accelerator DPG, coupling agent KH550 and CBp were modified by ball milling and plasma. The results showed that when the ratio of CBp to N326 was 40:15, the overall properties of NBR composites was better. Compared with the unmodified CBp/NBR composites, the change rate of tensile product, resilience and DIN abrasion of ball milling‐plasma modified CBp/NBR composites in oil environment were reduced by 52.96%, 12.81%, and 27.19%, respectively, and the tear strength after double damage by high temperature and oil bath was increased by 15.63%, which resulted in better oil and high temperature‐resistance. In summary, the ball milling‐plasma combined with DPG/KH550 modified CBp can not only replace N326 carbon black, but also realize the preparation of NBR composites with better oil and high temperature‐resistance.

Learning based model for predicting mechanical properties and sustainable filler band for NBR composites using lignin and carbon black

Experimental determination of mechanical properties of rubber composites, such as tensile strength and hardness, involves complex multistage preparation procedures that are laborious and expensive. In this study, a hybrid filler of carbon black (CB) along with a sustainable filler of lignin is added for reinforcement in the nitrile butadiene rubber (NBR) matrix, with the total filler content varying from 10 parts per hundred rubber (phr) to 80 phr. This work aims to develop a data-driven predictive model for the mechanical properties of rubber composites. An artificial neural network (ANN) model using multilayer feed-forward back-propagation has been created to forecast the tensile strength (Ts) and hardness (Hd) of rubber composites. The model predicts the uniaxial tensile response and hardness using input parameters that include total filler and lignin loading levels. The effectiveness of the suggested prediction method was demonstrated by statistical analysis using confidence intervals, showing a prediction error between 5.47% and 3.23% for the Ts and between 3.03% and 1.85% for Hd at 95% confidence intervals. A sustainable green band could be defined in the developed model, which is handy for designers to replace CB with lignin in various NBR based products, such as hoses, seals, etc., without compromising on tensile strength and hardness.

Hydrogen permeation behavior and mechanisms in nitrile butadiene rubber composites for hydrogen sealing

As the most widely used sealing component in hydrogen systems, rubber seals are affected by hydrogen over long-term service. Hydrogen molecules can dissolve into rubber materials and diffuse through the material. Studies have shown that adding fillers can enhance rubber's performance, improve its compatibility with hydrogen, and reduce the damage caused by hydrogen diffusion. Therefore, this study integrates experimental hydrogen permeation research with finite element modeling for nitrile butadiene rubber (NBR). The aim is to investigate the influence of filler properties on the microstructure, hydrogen permeation behavior, and hydrogen concentration distribution within NBR. Ultimately, the study elucidates the mechanisms governing hydrogen distribution evolution and permeation in NBR under hydrogen environments. The results indicate that the crosslink density of NBR filled with carbon black (NBR-CB) and silica (NBR-SC) is directly proportional to the filler content. NBR with higher filler content exhibits a lower hydrogen permeation coefficient and superior hydrogen barrier properties. In contrast to silica fillers, carbon black fillers demonstrate strong adsorption and a more pronounced barrier effect against hydrogen molecules, thereby enhancing the hydrogen barrier efficiency. The increase in carbon black's hydrogen solubility (from 2.2 × 10-4 to 16.9 × 10-4 cc(STP)·cm-3(polymer)·cmHg-1) effectively reduces the hydrogen permeation coefficient. In contrast, the rise in carbon black's hydrogen diffusion coefficient (from 0.1 × 10-6 to 4.1 × 10-6 cm2·s-1) exacerbates the overall hydrogen permeation coefficient of NBR-CB, thereby intensifying the hydrogen permeation process.

Revisiting the mechanism of rapid gas decompression failure in silica-reinforced NBR composites: Effect of interfacial phenomena

Sudden pressure drop in elastomers saturated with high temperature-high pressure gas produces a type of failure known as Rapid Gas Decompression (RGD). Understanding the relationship between the RGD and the material behaviour paves the way for better control of the RGD. It is the aim of the present work to study the effect of rubber-silica interfacial phenomena on the RGD resistance of nitrile butadiene rubber (NBR) composites. By grafting various degrees of a long-chain monofunctional silane onto the silica surface, composites having distinct levels of filler-induced mobility restrictions, and also controlled levels of interface strength were prepared. Also, to find the underlying mechanism responsible for controlling the RGD failure, an analysis of silica morphology, the cavitation strength, and the tear strength was performed for the composites. The RGD resistance was assessed under mild (70 MPa) and severe (cyclic test, 150 MPa) testing conditions using carbon dioxide gas. The obtained trend of the RGD damage was roughly correlated to the cavitation test, showing a higher resistance for the silica system having high filler-polymer interaction and bound rubber. It was suggested that the trend of RGD is more complicated to fully capture by a single physico-mechancial mechanism. Alternatively, inspired by the theory of fracture mechanics, it was suggested that the RGD can be better realized if the factors governing the driving force of RGD damage and the factors responsible for the resistance against the RGD are separated.

Molecular dynamics investigation on the thermal-oxidative aging and mechanical properties of nitrile butadiene rubber composites with molybdenum disulfide

Molecular dynamics investigation on the thermal-oxidative aging and mechanical properties of nitrile butadiene rubber composites with molybdenum disulfide

Phase field modeling of hydrogen release in nitrile-butadiene rubber composites after high-pressure hydrogen exposure

Experimental data showed that a simple diffusion model doesn't suffice to explain the hydrogen gas (H2) release kinetics in nitrile butadiene rubber (NBR) composites (one with no filler or plasticizer, one with plasticizer only, one with fillers and plasticizer, and one with fillers only) after exposed to hydrogen gas at a pressure of 27.6 MPa. In this work, we developed a phase field model that considers the effect of H2 gas bubble evolution on H2 release kinetics. With the model, we simulated the effect of thermodynamic and kinetics properties on the nucleation, growth, and shrinkage of gas bubbles and H2 release kinetics during and after decompression. The results demonstrated that (1) the model built upon certain thermodynamic and kinetics properties of a given material can well describe its H2 release kinetics measured in experiments, and (2) the model can predict the gas bubble evolution, which is associated with the material property degradation and structural failures, such as cracks and blisters, with accurate thermodynamic and kinetics properties or H2 release data from experiments.

Fluorographene and carbon nanotubes fillers reinforced nitrile butadiene rubber with enhanced mechanical, wear and oil resistant properties

AbstractIn this work, we prepared nitrile butadiene rubber (NBR) composites with fluorographene (FG) and carbon nanotubes (CNTs) as hybrid fillers by a solution‐blending method. The resulting composites xFG/yCNTs‐NBR, where x and y represent the loading of FG and CNTs respectively, show significantly improved physical and mechanical properties. The hybrid fillers can form a filler network in the rubber matrix, leading to efficient energy dissipation. As a result, when the mass ratio of FG to CNTs is 1:1 and the total filler loading is 20 phr, the tensile strength of 10FG/10CNTs‐NBR is as high as 12.1 MPa. Furthermore, due to inherent lubricating and oil‐repelling effects of FG, 10FG/10CNTs‐NBR shows an abrasion resistance index (ARI) of 187% and a volume change of 2.38% after 72 h of soaking in aviation oil, which are 24% higher and 48% lower than the corresponding values of unfilled NBR composites, respectively. These results indicate that the hybrid fillers can effectively enhance the mechanical, wear and oil resistant properties of the elastomer composites, which is conductive for application of the NBR‐based composites.

Polydopamine in‐situ polymerized on graphene oxide for nitrile butadiene rubber with high strength, elasticity and aging resistance

AbstractThe elasticity and aging resistance of nitrile butadiene rubber (NBR) will be reduced by reinforced filler. Herein, we report that polydopamine (PDA) polymerized in situ on graphene oxide (GO) to obtain polydopamine‐graphene oxide (PDA‐GO) nanofiller for simultaneously improving strength, elasticity and thermal oxidative aging‐resistant performance of NBR. The structure, composition and morphology of PDA‐GO and NBR composites were characterized. The effect of PDA‐GO on the performance of NBR was investigated. Results show that PDA microspheres improved the dispersion of GO in matrix. With incorporation 3 phr of PDA‐GO, the tensile strength of NBR raised from 3.8 to 9.2 MPa. It is satisfactory that the elasticity is also improved significantly. PDA‐GO/NBR composite equips better thermal oxidative stability and aging resistance. The tensile strength of 3 phr‐PDA‐GO/NBR after aging is even 3.4 MPa higher than that of unfilled NBR before aging. Our work proposes an insight for the manufacture of rubber composites with high strength, elasticity and aging resistance.Highlights GO modified by PDA is prepared via an in‐situ polymerization process. In situ polymerized PDA microspheres greatly promotes the dispersion of GO in NBR matrix. NBR filled with PDA‐GO shows a superior strength and elasticity simultaneously. PDA‐GO endows NBR with prominent performance in aging resistance.

Management of agricultural waste to manufacture biochar: An alternative reinforcing filler for carbon black in nitrile butadiene rubber composites

The carbon black (CB) used in rubber manufacturing and the unsafe disposal of agricultural waste are one of the causes of environmental pollution. Indeed, the production of one ton of CB produces about 2.4 tons of carbon dioxide. The conversion of these agricultural wastes into biochar (Bi) and using them as a reinforcing material is one of the trends that achieve sustainability and promote environmentally sound. Herein, the modified biochar (MBi) was obtained by chemo-mechanical treatment utilizing stearic acid for Bi which was produced from the pyrolysis of citrus trees to enhance its dispersion in nitrile butadiene rubber (NBR) composite. In addition, the present study scrutinized the influence of synergism between the MBi and CB as a filler in the NBR composites. The characterization of as-prepared samples was carried out by tracing the surface morphology, particle size analyzer, and identification of chemical bonds, as well as rheological, mechanical, aging, and electrical conductivity properties. The rheological studies showed that the optimum vulcanization time (tc90) did not significantly prolong for MBi-filled composites, which sequentially higher the benefits of the study by reducing energy consumed and thus, the process cost. In addition, the surface morphology and the mechanical data have distinguished that MBi particles were well-distributed along the matrix, as revealed by the tensile properties of the final composites. The electrical conductivity results manifested that MBi did not adversely affect the enhancement of conductivity. Whereas, the permittivity was increased due to the interfacial polarization between the filler and rubber matrix. In conclusion, the innovative filled-MBi elastomer composite would pave the way for an eco-friendly product that is valid for various applications.

A Modified Ground Rubber and its effect on Physico-mechanical and Dielectric Properties of Nitrile-Butadiene Rubber Composites For a Green Environment

A Modified Ground Rubber and its effect on Physico-mechanical and Dielectric Properties of Nitrile-Butadiene Rubber Composites For a Green Environment

Influence of the molecular structure of phenylamine antioxidants on anti-migration and anti-aging behavior of high-performance nitrile rubber composites

Abstract The structure of antioxidants significantly affects the anti-migration and thermal-oxidative aging properties of nitrile butadiene rubber (NBR) composites, which are crucial for applications in aerospace, biomedical, and fuel cell stack sealing industries. The findings reveal that the migration rate of N-(4-anilino phenyl) maleic imide (MC), with a reactive double bond, is only 15.6%, exhibiting the best extraction resistance. 2,4,6-Tris-(N-1,4-dimethylpentyl-p-phenylenediamino)-1,3,5-triazine (TMPPD), with a greater weight and dendritic structure, follows at 47.7%, while N-isopropyl-N′-phenyl-p-phenylenediamine (4010NA) performs the worst, with 77.8%. Furthermore, after thermal-oxidative exposure, the cross-link density of NBR composites increases, generating oxygenated substances, such as ethers, aldehydes, and acids. The addition of antioxidants in the composites improves the thermal-oxidative aging properties compared to those without any antioxidants. Moreover, antioxidants 4010NA and TMPPD display superior resistance to thermal-oxidative aging properties compared to antioxidant MC.

Simultaneously Improved Thermal Conductivity and Dielectric Properties of NBR Composites by Constructing 3D Hybrid Filler Networks

AbstractThis work aims to address the heat accumulation issue in electronic components during high‐frequency operation through the preparation of novel thermally conductive composites. First, polydopamine (PDA) and in‐situ growth of silver (Ag) nanoparticles are applied for the surface modification of graphene oxide (GO) and carbon nanotube (CNT) to prepare pGO@Ag and pCNT@Ag hybrid filler, respectively. Then, nitrile butadiene rubber (NBR) is chosen as the polymeric matrix and simultaneously incorporated with both pGO@Ag and pCNT@Ag to prepare polymeric composites with excellent thermal conductivity (TC) and dielectric constant (ɛr). Due to the construction of 3D heat conduction networks by utilizing 2D pGO@Ag and 1D pCNT@Ag, the fabricated NBR composites achieved the maximum TC of 1.0112 W/(mK), which is 636% higher than that of neat NBR (0.1373 W (mK)−1). At the filler loading of 9 vol%, the TC of pGO@Ag/pCNT@Ag/NBR composite is 152% that of GO/CNT/NBR composite (0.6660 W (mK)−1). Moreover, due to electron polarization effect of GO and CNT and micro‐capacitor effect of Ag nanoparticles, a large ɛr of 147.12 is attained at 10 Hz for NBR composites. Overall, the development of dielectric polymer materials with high TC is beneficial for enhancing the service life and safety stability of the electronic components.

A study on microwave absorption properties of polyaniline/nitrile rubber/graphene/Fe3O4 composites with a thickness of 0.7 mm and high flexibility

AbstractThe genotoxic effect of microwave radiation on humans is one of the leading causes of some diseases like cancer. Despite many reported materials for microwave absorption, there is still a demand for a super‐thin and flexible microwave absorber. In the present work, we synthesized Fe3O4/graphene/polyaniline/nitrile butadiene rubber composites with a thickness of 0.7 mm using a melt mixing method. Then, we comprehensively studied the electromagnetic and microwave absorption properties of the composites from 8 to 12 GHz. The composite with 38 wt% Fe3O4 and 6 wt% graphene exhibited the highest microwave absorption of more than 8 dB in the entire range of 8–12 GHz, with a minimum reflection loss of −14 dB at 10.3 GHz. By increasing the weight content of Fe3O4 and graphene, the imaginary part of dielectric permeability and magnetic permeability initially went up and then declined, resulting in poor impedance matching. Hence, we precisely controlled the weight content of the fillers to reach the highest impedance matching and attenuation constant. Consequently, this work opened up a unique way for developing super‐thin, lightweight, flexible microwave‐absorbing materials.

Synergistic Effect of Partial Replacement of Carbon Black by Palm Kernel Shell Biochar in Carboxylated Nitrile Butadiene Rubber Composites.

With the rapid development of the palm oil-related industry, this has resulted in the high production of palm oil waste. The increasing amount of palm oil waste has become an alarming issue in which researchers have carried out studies that this palm oil waste has the potential to be used as a biomass source. Carbon black (CB) is the most preferred reinforcing filler in the rubber industry but it has a disadvantage where CB is carcinogenic and a petroleum-based product. Hence CB is less sustainable. Palm kernel shell (PKS) derived from palm oil waste can be turned into palm kernel shell biochar (PKSBc) which can potentially be a value-added, sustainable biofiller as reinforcement in rubber composites. In this study, PKSBc is hybridized with CB (N660) at different loading ratios to be filled in carboxylated nitrile butadiene rubber (XNBR). This study aims to elucidate the effect of the varying ratios of hybrid CB/PKSBc on the rheological properties, abrasion resistance, and hardness of XNBR composites. In this study, both CB and PKSBc are incorporated into XNBR and were then cured with sulphur. The composites were prepared by using a two-roll mill. Different compositions of hybrid CB/PKSBc were incorporated. The rheological properties and physicomechanical properties, such as abrasion resistance and hardness of the vulcanizates, were investigated. Based on the results, as the loading ratio of PKSBc in hybrid CB/PKSBc increases, the cure time decreases, and the cure rate index increases. The abrasion resistance and hardness values of vulcanizates were maintained by the high loading of PKSBc which was due to the porous structure of PKSBc as shown in the morphological analysis of PKSBc. The pores of PKSBc provided mechanical interlocking to reduce volume loss and maintain the hardness of vulcanizates when subjected to force. With this, PKSBc is proven to be a semi-reinforcing filler that could not only act as a co-filler to existing commercialized CB, but PKSBc could also fully substitute CB as reinforcement in rubber, specifically XNBR as it is able to provide high abrasion resistance and hardness to the rubber composites. This would mean the performance of PKSBc is comparable with CB (N660) when it comes to maintaining the physicomechanical properties of XNBR composites in terms of abrasion resistance and hardness. Therefore, this approach of using eco-friendly filler derived from palm oil agricultural waste (PKSBc) can reduce the abundance of palm oil waste, be a sustainable alternative to act as a co-filler in hybrid CB/PKSBc to decrease the usage of CB, and helps to enhance the quality of existing rubber-based products.

Molecular Simulation and Experimental Study on the Damping and Aging Properties of 4010NA/Hydrogenated Nitrile Butadiene/Nitrile Butadiene Rubber Composites

AbstractThe effects of N‐isopropyl‐N′‐phenyl‐phenylenediamine (4010NA) content on the damping and aging properties of hydrogenated nitrile butadiene rubber (HNBR)/nitrile butadiene rubber (NBR) (abbreviated as H‐NBR) matrix are studied via molecular simulation and experiments. The effects of 4010NA addition on the damping and aging properties of H‐NBR are analyzed by molecular simulation using solubility parameters (δ), hydrogen bonds, free volume fraction (FFV), binding energy (Ebinding), hydrogen bond dissociation energy (ΔG), and mean square displacement (MSD). The damping, mechanical, and thermo‐oxygen aging properties of the 4010NA/H‐NBR composites are studied experimentally using infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The results indicate that 4010NA has good compatibility with HNBR and NBR, and the addition of 4010NA can effectively improve the damping properties of H‐NBR. When 4010NA is added at 32 phr, the composite has better damping properties, mechanical properties, and aging resistance, which provides a new insight for the construction of high performance elastomer composites.

Molecular dynamics simulations of defective carbon nanotubes on the aging and friction properties of nitrile butadiene rubber composites

AbstractThe thermal‐oxidative aging (TOA) and tribological properties of rubber had attracted attention in the petrochemical field. In this study, the mechanical and tribological properties of defect‐free, Stone–Wales (SW), and single adatom (SA) defective carbon nanotubes (CNTs)/nitrile butadiene rubber (NBR) composites were investigated using molecular dynamics simulations. Poly (1,2‐dihydro‐2,2,4‐trimethyl‐quinoline) (antioxidant RD) was added to the composites to analyze their TOA mechanisms. Antioxidant RD provided the best protective effect in SW‐CNTs/RD/NBR composites, and their TOA properties were enhanced. In addition, the Young's modulus, bulk modulus, and shear modulus, friction coefficient, and wear rate of the SW‐CNTs/RD/NBR composites were improved. The effects of SW‐CNTs on the RD/NBR composites were elucidated from a molecular perspective. The surface structures of three groups of CNTs were analyzed, and the SW‐CNTs exhibited a stronger adsorption ability and binding effect. It was determined that the antioxidant RD and NBR could be more stably dispersed between the molecular chains in the SW‐CNTs/RD/NBR composites.

Improving thermal‐oxidative stability of nitrile butadiene rubber composites by surface modification of zirconium phosphate

AbstractZirconium phosphate (α‐ZrP) was modified by o‐phenylenediamine (OPD) grafting to its surface, named ZPD, and used to improve thermal‐oxidative stability of nitrile butadiene rubber (NBR) by direct blending method. The results of Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), X‐ray diffraction, and contact angle test, demonstrated that OPD was grafted to the surface of α‐ZrP successfully. Scanning electron microscopy results showed that OPD could effectively improve the interaction between α‐ZrP and NBR and a better the dispersion of α‐ZrP in the rubber matrix. The fracture strength of the NBR composites was increased by 3.3 Mpa with the addition of 3 phr ZPD fillers, respectively, compared with unmodified NBR/α‐ZrP composites. In addition, TGA, DMA, and FWO analysis showed ZPD fillers, combined lamellar barrier of α‐ZrP with radical trapping ability of OPD, could retard oxidative cross‐linking and fracture reaction of rubber chains, and improve the thermal‐oxidative aging resistance of the NBR composites. This work provides a practical and effective methodology for surface modification of α‐ZrP and preparation of high‐performance NBR composites.

Bioinspired Rubber Composites with Mechanical Robustness, Recyclability, and Shape Memory Properties

AbstractVitrimers display great potential for application in various industries thanks to their high strength, reprocessability, and multi‐functions. However, it is still quite a challenge to fabricate rubber vitrimers as the facile designs in reversible crosslinking networks are always critical. Herein, inspired by mussel byssus, heterogeneous coordination networks are constructed in nitrile butadiene rubber (NBR) to develop novel vitrimeric structures composed of metal‐phenolic network (MPN) granules with dense zinc ions (Zn2+)–tea polyphenol (TP) bonds and a soft matrix containing few Zn2+cyano group (CN) coordination bonds. The resulting NBR composites show tunable reinforcement simply by altering the amount of Zn2+ ions. The reversibility of complexations endows the composites with good plasticity, recyclability, and stable shape memory properties. Plasticity at high temperatures changes vitrimeric networks, producing larger and spindle‐like MPN granules owing to their secondary self‐assembly. Despite these variations, the vitrimeric composites still maintain engineering plasticity‐based shape memory properties at a relatively large strain. Therefore, it is believed that the biomimetic strategies can well fabricate rubber composites with high strength, reprocessable, and shape‐memory performance.

Oriented molybdenum disulfide-silica/hydrogenated nitrile butadiene rubber composites: Effects of nanosheets on mechanical and dielectric properties

A series of non-covalently functionalized molybdenum disulfide-silica (f-MoS2-SiO2) nanocomposites was prepared by an in-situ assembled method and used to fabricate the oriented molybdenum disulfide-SiO2/Hydrogenated Nitrile Butadiene Rubber (f-MoS2-SiO2/HNBR) composites. The characterization results show the synergistic dispersion between the functionalized molybdenum disulfide (f-MoS2) nanosheets and SiO2 nanoparticles. The addition of f-MoS2 nanosheets can improve the dispersion of fillers in the rubber matrix and weaken the filler network. The non-covalently functionalization improves the interface interaction between f-MoS2 nanosheets and the rubber matrix. Furthermore, the tensile strength of f-MoS2-SiO2/HNBR is 65.9% higher than that of SiO2/HNBR by adding 1.0wt% of f-MoS2. At the same time, the dielectric constant of f-MoS2-SiO2/HNBR is increased by 23.7% compared to SiO2/HNBR due to the micro-capacitor structure of parallel f-MoS2 nanosheets in the rubber matrix. Our work provides new ideas for the development of high-performance elastomer materials.

Investigation of the Compatibility and Damping Performance of Graphene Oxide Grafted Antioxidant/Nitrile-Butadiene Rubber Composite: Insights from Experiment and Molecular Simulation.

Rubber damping materials are widely used in electronics, electrical and other fields because of their unique viscoelasticity. How to prepare high-damping materials and prevent small molecule migration has attracted much attention. Antioxidant 4010NA was successfully grafted onto graphene oxide (GO) to prepare an anti-migration antioxidant (GO-4010NA). A combined molecular dynamics (MD) simulation and experimental study is presented to investigate the effects of small molecules 4010NA, GO, and GO-4010NA on the compatibility and damping properties of nitrile-butadiene rubber (NBR) composites. Differential scanning calorimetry (DSC) results showed that both 4010NA and GO-4010NA had good compatibility with the NBR matrix, and the Tg of GO-4010NA/NBR composite was improved. Dynamic mechanical analysis (DMA) data showed that the addition of GO-4010NA increased the damping performance of NBR than that of the addition of 4010NA. Molecular dynamics (MD) simulation results show GO-4010NA/NBR composites have the smallest free volume fraction (FFV) and the largest binding energy. GO-4010NA has a strong interaction with NBR due to the forming of hydrogen bonds (H-bonds). Grafting 4010NA onto GO not only inhibits the migration of 4010NA but also improves the damping property of NBR matrixes. This study provides new insights into GO grafted small molecules and the design of high-damping composites.