Nitrile Butadiene Rubber Latex Research Articles

A low-temperature stretchable XNBR film containing Li-TFSI doped PEDOT:PSS for electromagnetic interference shielding

Stretchable electromagnetic shields have garnered significant attention in the burgeoning field of flexible devices, while traditional strategies developed to maintain adequate electromagnetic shielding performance under large strains are more challenging at low temperatures. Herein, elastic electromagnetic shielding films with segregated conductive network were produced by an extremely simple method of evaporating carboxylated nitrile butadiene rubber latex containing lithium bis(trifloromethanesulfonyl)imide doped poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate). The films of 0.2 mm in thickness are highly stretchable at −20 °C and exhibit an electromagnetic interference shielding efficiency of more than 30 dB at 100 % strain and −10 °C. These properties underscore the potential of the films as effective stretchable EMI shields in low-temperature conditions. Experiments demonstrating the films' ability to block Bluetooth signals from ESP32 chip microcontrollers and electromagnetic waves from Tesla coils further confirm their usefulness, highlighting the practicality of protecting flexible devices in cold environments.

Study on the structural and properties of composite films prepared by blending EUL and NBRL

In order to address issues such as poor dimensional stability caused by low modulus and tensile stress of nitrile butadiene rubber latex (NBRL) films, as well as poor wearing comfortability due to its good adhesion to the human skin, and the inability to meet the requirements of medical special occasions due to low tensile and tear strength. A new strategy is proposed to develop the Eucommia ulmoides latex (EUL) by using the emulsion solvent evaporation technique. EUL was then blended into the NBRL, successfully preparing the NBR/EUG composite latex film. As the Eucommia ulmoides gum (EUG) content increased from 0 to 40 %, the crystallinity of the NBR/EUG composite latex film gradually increased from 0 to 10 % or so. The tensile strength increases from 5.17 MPa to 15.94 MPa, the tear strength increases from 22.17 kN/m to 37.79 kN/m, the modulus increases from 6.40 MPa to 24.80 MPa. The very important point is that the elongation at break keep stable with the increase of EUG. On the contrary, the elongation at break will decrease with addition of conventional fillers into the latex, such as silica. These enhance mechanical properties and keep the dimensional stability of the film. Therefore, it can be utilized for the development of latex film products with high modulus and big deformation, such as sky balloon and foam mattress. Additionally, the crystalline nature of EUG effectively reduces the adhesion force on the surface of the composite latex film, thus improving its compatibility with human skins. This meets the requirements of special environments, such as medical gloves. At last, as a kind of biobased latex, it can increase the content of renewable resources and reduce the carbon emission of NBRL.

Effect of ionic liquid modified carbon nanotubes on the properties of nitrile butadiene rubber and nitrile butadiene latex nanocomposites

AbstractMultiwalled carbon nanotubes (MWCNT) were widely used in nano‐polymer materials due to their excellent electrical and thermal conductivity and mechanical properties. However, the dispersion of MWCNT in the rubber matrix was usually poor due to their large aspect ratio and tendency to agglomerate. The main innovation of this technology was that the non‐covalent modification did not destroy the surface structure and original properties of MWCNT, which was a breakthrough compared to the previous covalent modification. The obtained IL‐MWCNT was still distributed in the water a month after sonication. The microstructural development of the filled network and the uniform dispersion of MWCNT in the presence of IL were analyzed by TEM. The apparent physical (cation–π/π–π) interactions between MWCNT and IL were characterized by Raman spectroscopy and thermal gravimetric analysis (TGA). The high‐performance composites of IL‐MWCNT and nitrile butadiene rubber (NBR) or nitrile butadiene rubber latex (NBRL) were prepared by the liquid latex blending method. The mechanical properties of the composites were improved due to the uniform distribution of IL‐MWCNT in the matrix. As found in this work, the addition of 3 phr of IL increased the mechanical properties of the composites significantly. The continued addition of IL affects the dispersion of MWCNT in the composites due to the plasticizing and diluting effects of IL, which results in a decrease in the mechanical properties. This study provides a simple, environmentally friendly method for the development of IL‐MWCNT composites.

Selective hydrogenation of nitrile butadiene rubber latex using Catmetium®RF 4 catalyst

Hydrogenation of nitrile butadiene rubber (NBR) latex is an important topic in the field of chemical modification of unsaturated diene-based polymers. At present, the main challenge that restricts the large-scale production of hydrogenated nitrile rubber (HNBR) via latex hydrogenation way is how to reduce or even eliminate the use of organic solvents and to achieve a high rate of hydrogenation combined with a low amount of catalyst. We found a high-efficiency catalyst, i.e., catMETium®RF 4, which can directly hydrogenate NBR latex. The effects of temperature, hydrogen pressure, concentration of [CC]0 and agitation speed on the rate of hydrogenation were fully investigated. It was found that by using catMETium®RF 4 catalyst to prepare HNBR, the rate of hydrogenation of NBR latex can be increased drastically to achieve a high CC conversion of 95 mol% with a very low catalyst level of 0.02 wt%, which greatly decrease the demand on the recovery of a homogeneous catalyst from HNBR matrix. In addition, the hydrogenation of HNBR latex by catMETium®RF 4 was completely free of organic solvents and no cross-linking was found.

Hydrogenation of Carboxyl Nitrile Butadiene Rubber Latex Using a Ruthenium-Based Catalyst

Hydrogenated carboxyl nitrile rubber (HXNBR) is endowed with superior mechanical performance and heat–oxygen aging resistance via emulsion hydrogenation of its precursor, i.e., carboxyl nitrile rubber (XNBR). Herein, a ruthenium-based catalyst was prepared to achieve the direct catalytic hydrogenation of XNBR latex. The effects of a series of hydrogenation conditions, such as catalyst dosage, solid content and reaction temperature, as well as the hydrogen pressure, on the hydrogenation reaction were investigated in detail. We found that the hydrogenation rate fell upon increasing the solid content of the XNBR latex, with an XNBR conversion rate of 95.01 mol% in 7 h with 11.25 wt% solid content. As the reaction temperature was increased, the hydrogenation rate first increased and then decreased. The fastest reaction hydrogenation rate was reached at 140 °C, with an XNBR conversion of 95.10 mol% in 5 h. The hydrogenation rate was positively related with the hydrogen pressure employed in the reactor. In view of the safety and cost, a pressure rate of 1300 psi was considered optimal. Similarly, the hydrogenation rate can also be enhanced by adding more catalyst. When 0.05 wt% catalyst was added, the fastest hydrogenation rate was achieved. In summary, the following optimum hydrogenation conditions were determined by using a synthesized ruthenium-based catalyst: 11.25 wt% solid content of XNBR latex, 140 °C of reaction temperature, 1300 psi of hydrogen pressure and 0.05 wt% catalyst. The vulcanization, mechanical performance, aging resistance and oil resistance of the produced HXNBR under the above reaction conditions were systematically investigated.

Utilization of oil palm empty fruit bunch cellulose fillers for biodegradable properties of carboxylated nitrile butadiene rubber latex films

The increase in latex gloves production in Malaysia has caused a landfill build-up due to its low biodegradable properties upon disposal. Meanwhile, oil palm biomass waste also shows a similar trend due to the global demand for palm oil. Therefore, the utilization of oil palm empty fruit bunch (OPEFB) cellulose fiber-filled carboxylated nitrile butadiene rubber (XNBR) latex is investigated. The OPEFB cellulose fillers are subjected to alkali and bleaching treatment to remove the wax, lignin, and hemicellulose. The treatment effectively removed most of the non-cellulosic components in OPEFB fibers. The XNBR latex was then compounded with different loading of OPEFB cellulose fillers (2phr, 4phr, 6phr, 8phr). The results obtained show as the OPEFB cellulose filler loading increases, the mechanical properties of latex films decrease due to the agglomeration of fillers that act as stress concentrations. After four weeks of soil burial, the biodegradable properties of XNBR latex films are enhanced with increasing filler loading as OPEFB fillers act as a source of nutrients for the biodegradation process by microorganisms. The balance in the mechanical and biodegradable properties is achieved at 4phr of OPEFB cellulose filler loading.

Oil palm empty fruit bunch cellulose fillers as alternative fillers for carboxylated nitrile butadiene rubber latex films

Malaysia is one of the largest contributors to oil palm plantations and industries, resulting in the generation of a lot of oil palm waste such as oil palm empty fruit bunch (OPEFB). The main goal of this research is to investigate the effect of the OPEFB cellulose as one of the alternative fillers in the carboxylated nitrile butadiene rubber (XNBR) latex films. The OPEFB waste was subjected to ultrasonic with alkali and bleaching treatment prior to addition in XNBR latex compounds. The ultrasonic treatment shows better removal of wax, hemicellulose and lignin but leads to breaking down the crystalline structure of the cellulose particles resulted in reduction of the mechanical properties of the OPEFB cellulose filled XNBR latex films. The OPEFB cellulose filled XNBR latex compound is then subjected to different zinc oxide (ZnO) loading. It found that the increase in zinc oxide loading enhanced the ionic crosslink formation but disrupt the covalent crosslink formation since most of the metal cations Zn2+ tend to form ionic clusters for the ionic crosslinks and Zn-cellulose complex. Overall, the OPEFB cellulose fillers shows positive impact as alternative fillers in XNBR latex films.

Optimization of compounding formulation for the development of high-preformance coating material using waste tire powder for gasket application

Nitrile butadiene rubber latex (NBRL) based gasket materials were extensively used in the past due to their excellent oil resistance, good abrasion resistance, and shock absorption as well as good high-temperature stability. Recently, carbon black has been introduced to further improve the oil absorption properties and thermal performance of the gasket materials which increased the total costing and makes the processing difficult due to the agglomeration of carbon black in NBRL. Thus, in this research, waste tire powder (WTP) was introduced to develop high-performance coating materials as an alternative to carbon black in NBRL gasket material. Optimization of new compounding formulation has been carried out by manipulating the WTP loading and hybrid WTP-carbon black filler loading. The filler loading was selected based on the desired surface texture and coating thickness. The experience was also carried out by varying the WTP, Sulphur, and plasticizer loading. The desired surface texture and thickness of coating materials were developed at WTP loading of 80phr and 90phr. Whereas, the optimum Sulphur loading was achieved at 1phr - 2phr, and plasticizer loading of 10phr and 15phr. From the experiments carried out, the optimum loading of WTP was 90phr which gives a fully contained gasket composite. Furthermore, DOP optimum loading is 15phr which gives a smooth surface appearance. Lastly, Sulphur with 1phr gives a more even surface texture as compared to 2phr loading.

Cellulose‐Nanofiber‐Reinforced Rubber Composites with Resorcinol Resin Prepared by Elastic Kneading

AbstractA resorcinol resin/water dispersion and a rubber latex are added to 1% 2,2,6,6,‐tetramethylpyperidine‐1‐oxyl (TEMPO)‐oxidized cellulose nanofibers (TEMPO‐CNFs) dispersed in water, followed by oven drying at 40 °C for 20 h to prepare a dried TEMPO‐CNF/resorcinol resin/latex rubber (DTRL) mixture with a weight ratio of 1/0.5/3. DTRL is then added to a nitrile‐butadiene rubber (NBR) or a carboxy group‐containing NBR (X‐NBR) sheet, and the mixture is kneaded by a two‐roll mill at 20–30 °C with high shear forces. The tensile strength and Young's modulus of the crosslinked DTRL/rubber composite sheets remarkably increased from 10 and 12 MPa, respectively, for the reference sheet to 24 and 82 MPa, respectively, for the DTRL/rubber composite sheets containing ≈10 vol% TEMPO‐CNFs. Scanning electron microscopy revealed that no TEMPO‐CNF agglomerates are present in the DTRL/rubber composite sheets. The tensile properties of the composite sheets are the best when a X‐NBR sheet and NBR latex are used as the matrix rubber and latex in DTRL preparation, respectively. When water‐extracted DTRL (WDTRL, mass recovery ratio ≈94%) is used in place of DTRL, the WDTRL/rubber composite sheets show sufficient water resistance, while the tensile properties are almost the same as those of the DTRL/rubber composite sheets.

Fatty acid coated iron oxide nanoparticle: Effect on stability, particle size and magnetic properties

Iron oxide nanoparticles (IONP) have been used as a magnetic base for polymeric composites. However, the magnetic properties of IONP are not fully exploited due to the difficulties to obtain a good dispersion and high stablity within the polymeric matrix. The objective of this study is to improve the stability, dispersive ability and separability of IONP by fatty acid coating. Fatty acid coated iron oxide nanoparticle (C-IONP) has been selected due to its hydrophobicity and hydrophilicity characteristics and consequently useful to be incorporated with nitrile butadiene rubber (NBR) as a polymeric compound model. The facile precipitation method has been used to synthesize C-IONP with good polydispersity of iron oxide nanoparticle (IONP) and high compatibility with polar and non polar medium was addressed. Iron (II) sulphate heptahydrate and ammonium hydroxide were selected as precursors to synthesize IONP at 60 °C at 1.5 h aging time and subsequently coated with series of fatty acids (oleic, capric, myristic, palmitic and stearic acids). It is observed that, oleic acid C-IONP has excellent compatibility in water and NBR latex medium, with small hydrodynamic size and narrow particle size distribution. This is due the existence of double bond in oleic acid backbone chain. The magnetization saturation of oleic acid C-IONP was 54.53 emu/g hence it can be incorporated to NBR latex. This therefore demonstrated that, highly magnetic polymeric composite could be produced with good and homogeneously dispersed and stable IONP.

The Effect of Acid Hydrolyzed Sago Starch on Mechanical Properties of Natural Rubber and Carboxylated Nitrile Butadiene Rubber Latex

Abstract Sago starch is an organic filler that provide biodegradable properties to natural and synthetic rubber latex thin film products upon disposal. There is antagonism effect between biodegradability and mechanical properties of sago filled XNBR latex films where it prone to agglomerate and incompatible with latex system which, eventually reduced the mechanical properties of the latex films. The objective of this research is to develop a small particle size sago starch to improve the mechanical properties and biodegradability of latex films upon disposal. The native sago starch (NSS) was hydrolyzed with different hydrolysis condition at different temperature, acidity and duration. The results showed that the optimum synthesis parameters of preparation acid hydrolysis sago starch was at 2.18 M sulphuric acid under non heated condition (27°C) for 7 days. The particle size of native sago starch is 1.233 µm and it reduced to 0.313 µm under same condition. It was found that the AHSS has improved mechanical properties and swelling resistance of latex films as compared to NSS filled NR latex films and NSS filled XNBR latex films. The biodegradation assessment by mass loss analysis indicates AHSS filled NR latex and XNBR filled latex films has higher degree of biodegradation rate. Overall addition of AHSS has increased the mechanical and biodegradable properties of both type of latex films (NR and XNBR) compared to NSS.

Acrylonitrile butadiene nanocomposites containing different clays by latex compounding method

Considering elastomers nanocomposites, most of the works are focused on natural rubber, styrene butadiene rubber and rubber blends, while few of them deal with nitrile butadiene rubber (NBR). This article presents the reinforcing effect of two raw sodic montmorillonites (Mts) and one organoclay on NBR matrix prepared by the latex compounding method. Raw Mts increase the mechanical properties of neat matrices. A pseudoplastic behavior is observed with the incorporation of clays into the NBR latex, indicating interactions between polymer chains and clay sheets, in agreement with the results of zeta potential analysis. X‐ray diffraction evaluates changes in the interlayer distance of the clay, indicating the NBR intercalation phenomenon in all cases. Matrices with different clay proportions present variations in the mechanical properties, depending if the aggregation phenomenon is promoted. Morphological analysis of clays and nanocomposites as well as thermal analysis were performed. The variation in mechanical properties after an aging process was studied, evaluating the effects on the tensile strength, ultimate strain and 300% modulus. POLYM. ENG. SCI., 59:736–744, 2019. © 2018 Society of Plastics Engineers

Preparation and characterization of Bi2O3/XNBR flexible films for attenuating gamma rays

A bismuth oxide (Bi2O3)-dispersed carboxylated nitrile butadiene rubber (XNBR) flexible film was prepared as a flexible lead-free material for gamma ray (γ-ray) attenuation. However, obtaining a uniform and stable dispersion of Bi2O3 in carboxylated nitrile butadiene rubber latex (XNBRL) is a challenge due to sedimentation induced by the remarkable density differences. Here, this challenge was approached by reducing the Bi2O3 particle radius, increasing the viscosity of the latex, and adding a dispersant. The experimental results confirmed that Bi2O3 was well dispersed in the XNBRL in the concentration range of 30–70 wt%. The mechanical properties demonstrated that the Bi2O3/XNBR flexible films had a good resistance to oil, acid, alkali, and hot air. The linear attenuation coefficients of the Bi2O3/XNBR flexible films obtained from the experiments were in good agreement with the calculated values. The attenuation efficiencies of the Bi2O3/XNBR flexible films with different thicknesses and Bi2O3 contents were investigated for a few different γ-ray energies. These results showed that the Bi2O3/XNBR flexible films have wide application prospects for low-energy γ-ray attenuation.

Multi-walled carbon nanotube reinforced self-crosslinking hydrogenated carboxylated nitrile butadiene rubber latex film with improved properties

ABSTRACTA dielectric self-crosslinking hydrogenated carboxylated nitrile butadiene rubber (HXNBR) latex film was prepared by diimide reduction hydrogenation of XNBR latex and the doping of multi-walled carbon nanotube (MWCNT). The structures of the HXNBR and XNBR were characterised by Fourier transform infrared spectroscopy (FTIR) and 1HNMR, confirming the successful hydrogenation of XNBR. The mechanical, thermal, and electrical properties of the prepared HXNBR latex films were studied, and the HXNBR latex film reinforced by only 3 phr MWCNTs exhibited improved mechanical, thermal, and dielectric properties.

The properties of rice bran carbon/nitrile‐butadiene rubber composites fabricated by latex compounding method

Nitrile‐butadiene rubber (NBR) composites incorporated with four kinds of rice bran carbon (RBC), with different particle sizes, were fabricated by latex compounding method based on the superior dispersion ability of RBCs in NBR latex. Field emission scanning electron microscopy was employed to confirm the uniform dispersion of filler in the matrix. The mechanical property and oxygen transmission rates of the vulcanizates were studied. The RBC with smallest particle size exhibited best reinforcing performance. Then RBC/NBR composites, with different concentration of (3‐mercaptopropyl) trimethoxysilane (MPTMS), were prepared by a facile process. MPTMS, for the purpose of enhancing the compatibility between the filler and matrix, was incorporated into the rubber by an in situ method. Morphological analysis, Raman spectroscopy, and dynamic mechanical analysis tests confirmed the improvement of the interfacial interactions between the RBC and NBR matrix. The incorporation of MPTMS significantly enhanced the mechanical and oxygen barrier properties of the RBC/NBR composites. Both, the mechanical property and oxygen barrier abilities increased as the loading of the MPTMS increased, within a range of 0–9 phr. POLYM. COMPOS., 2016. © 2016 Society of Plastics Engineers

Effects of silane coupling agents on the properties of bentonite/nitrile butadiene rubber nanocomposites synthesized by a novel green method

Effects of different silane coupling agents on the mechanical strength, tribological properties, thermal behaviors, swelling properties and rheological properties of bentonite (Bent)/nitrile butadiene rubber (NBR) nanocomposites were explored. The nanocomposites were fabricated with an innovative green method in NBR latex. The composition of the nanocomposites was determined by Fourier transform infrared spectroscopy (FT-IR). The intercalated/exfoliated structure and the dispersion of Bent in rubber matrix were characterized with X-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM). It is revealed that different functional groups from the silanes were effective to the properties of the nanocomposites mainly because of their different interactions with the rubber matrix. Mercaptopropyltrimethoxysilane (MPTMS) showed attractive effects on mechanical modulus, tribological properties and swelling properties. Incorporation of bis-[3-(triethoxysilyl)propyl]tetrasulfide (TESPT) resulted in the highest elongation at break. With octadecyltrimethoxysilane (OTMS), the degradation temperature of the nanocomposite was noticeably elevated due to its “barrier effect”.

Effect of magnetic and thermal properties of iron oxide nanoparticles (IONs) in nitrile butadiene rubber (NBR) latex

Nitrile butadiene rubber (NBR) gloves are one of the most important personal protective equipments but they are possible to tear off and contaminate food or pharmaceutical and healthcare products during manufacturing and packaging process. High tendency of torn glove remaining in food or products due to white or light flesh-coloured glove is not easy to be detected by naked eyes. In this paper, iron oxide nanoparticles (IONs) selected as additive for NBR to improve its detectability by mean of magnetic properties. IONs synthesized via precipitation method and compounded with NBR latex before casting on petri dish. The properties of IONs were investigated by X-ray Diffractometry (XRD), Transmission Electron Microscope (TEM), Raman Spectroscopy and Vibrating Sample Magnetometer (VSM). Meanwhile NBR/IONs composites were studied by Thermogravimetry Analysis (TGA), Differential Scanning Calorimetry (DSC) and Vibrating Sample Magnetometer (VSM). It observed that, synthesized IONs shows of 25.28nm crystallite with 25.86nm semipherical (changed as) shape. Meanwhile, Magnetite and maghemite phase are found in range of 670cm−1 and 700cm−1 respectively, which it contributes magnetization saturation of 73.96emu/g at 10,000G by VSM. Thermal stability and magnetic properties were increased with incorporating IONs into NBR latex up to 20phr. NBR/IONs 5phr has the optimum thermal stability, lowest glass transition temperature (−14.83°C) and acceptable range of magnetization saturation (3.83emu/g at 10,000G) to form NBR gloves with magnetic detectability.

The physical and degradation properties of starch-graft-acrylonitrile/carboxylated nitrile butadiene rubber latex films

Starch-graft-acrylonitrile (ANS) is compounded with carboxylated nitrile butadiene rubber (XNBR) latex. The control XNBR and the ANS/XNBR latex films were prepared through a coagulant dipping process. The films were subjected to ageing and soil burial procedures. For the biodegradation experiment, the surface of the film was assessed after the 2nd, 4th and 8th week of soil burial. The ANS, XNBR, and ANS/XNBR colloidal stability were determined with a Malvern® Zetasizer. For the dipped latex films, the mechanical, morphological and thermal properties were analyzed. The addition of ANS into the XNBR latex increased the stability of the colloidal dispersions, decreased the latex film tensile strength, but increased the elongation at break due to the bipolar interaction of the ANS and XNBR particles. The ANS/XNBR latex films aged faster than the control films while the morphological analysis showed the existence of a starch crystal region and the formation of microbial colonies on the surfaces of the films. Based on the TGA–DTA curves, a higher ΔT was observed for the ANS/XNBR latex films signifying high thermal energy needed for the film to thermally degrade.

Organic solvent-free catalytic hydrogenation of diene-based polymer nanoparticles in latex form: Mass transfer of hydrogen in a semibatch process

The mass transfer process of hydrogen during hydrogenation of diene-based latex nanoparticles remains as one of the most discussed and sought-after research topics particularly for potential commercial processes carried out in a semibatch reaction mode. In this research, in-house prepared nitrile butadiene rubber (NBR) nanoparticle latices were prepared as the substrate for the subsequent hydrogenation experiments. The mass transfer pathway of hydrogen molecules in a gas (hydrogen)–liquid (water)–solid (polymer) three phase hydrogenation system under semibatch operation was examined, wherein the hydrogen transports from the bulk gas phase to an intermediate liquid phase, and then to the solid polymer phase. The mass transfer of hydrogen across the interfacial surfactant layer at the water/polymer interface was studied. A one-dimensional, moving boundary model was developed to describe the diffusion of hydrogen into the polymer nanoparticles by incorporating the level of bound hydrogen in the aqueous phase and the mass diffusivity of hydrogen in the polymer phase. Our results show that the mass transfer of hydrogen cannot account for the rate-determining step of NBR latex hydrogenation. This research report provides some further insight into the mass transfer of hydrogen during catalytic latex hydrogenation.

Recovery of Wilkinson’s Catalyst from Hydrogenated Nitrile Butadiene Rubber Latex Nanoparticles

Three different chelating ligands were used to separate Wilkinson’s catalyst from HNBR nanoparticles in latices. N,N,N′,N′,N′′-pentamethyldiethylenetriamine was found to be very effective in removing the catalyst. HNBR particle size and the extraction temperature on catalyst removal were investigated. The mechanism involved in the separation process was elucidated. This study promotes the possible commercialization of the green latex direct hydrogenation technique.