Acrylonitrile Butadiene Rubber Composites Research Articles

Double percolation behavior through the preferential distribution of conductive black in polymer blends to boost electrical properties and EMI shielding effectiveness

The preferential distribution of the filler in the polymer blends leads to a lower percolation threshold in comparison to a single polymer matrix with random filler distribution. Poly(ethylene methyl acrylate) (EMA) and carboxylated acrylonitrile butadiene rubber (XNBR) composites of EMA-XNBR (EX) with a variable amount of conductive carbon black (Vulcan XC 72; VXC) has been prepared by conventional melt blending. These composites have superior electromagnetic interference (EMI) shielding effectiveness to attenuate the hazardous effects and save society from proliferating electromagnetic radiation. The suitable distribution of carbon black lowers the electrical percolation threshold of 12.5 phr by the formation of interconnected architecture following the two-step percolation phenomenon and results in an improved EMI SE of 33.5 dB. The morphological analysis demonstrates that the formation of a polymer-filler network of VXC in an EX technologically compatible blend increases the mechanical and thermal stability of composites by retaining their flexibility, which facilitates the application of EXV composites in techno-commercial fields.

Coral derived nano calcium carbonate incorporated acrylonitrile butadiene rubber composites: Green look at properties

Coral derived nano calcium carbonate incorporated acrylonitrile butadiene rubber composites: Green look at properties

High Performance of Titanium Dioxide Reinforced Acrylonitrile Butadiene Rubber Composites

Recently, dielectric elastomer actuators (DEA) have emerged as one of the most promising materials for use in soft robots. However, DEA needs a high operating voltage and high mechanical properties. By increasing the dielectric constant of elastomeric materials, it is possible to decrease the operating voltage required. Thus, elastomeric composites with a high dielectric constant and strong mechanical properties are of interest. The aim of this research was to investigate the effect of titanium dioxide (TiO2) content ranging from 0 to 110 phr on the cure characteristics, and physical, dielectric, dynamic mechanical, and morphological properties of acrylonitrile butadiene rubber (NBR) composites. The addition of TiO2 reduced the scorch time (ts1) as well as the optimum cure time (tc90) but increased the cure rate index (CRI), minimum torque (ML), maximum torque (MH), and delta torque (MH - ML). The optimal TiO2 content for maximum tensile strength and elongation at break was 90 phr. Tensile strength and elongation at break were increased by 144.8% and 40.1%, respectively, over pure NBR. A significant mechanical property improvement was observed for TiO2-filled composites due to the good dispersion of TiO2 in the NBR matrix, which was confirmed by scanning electron microscopy (SEM). Moreover, incorporating TiO2 filler gave a higher storage modulus, a shift in glass transition temperature (Tg) to a higher temperature, and reduced damping in dynamic mechanical thermal analysis (DMTA). The addition of TiO2 to NBR rubber increased the dielectric constant of the resultant composites in the tested frequency range from 102 to 105 Hz. As a result, TiO2-filled NBR composite has a high potential for dielectric elastomer actuator applications.

Physicochemical Studies on the Effect of Hexamine Addition and Ratio on the Properties of Acrylonitrile Butadiene Rubber Composites

the manuscript contents is including the following of the title, author, affiliations, abstract, introduction, results and discussion, preparation of composites, ATR-FTIR characterization, AFM characterization, thermal behavior investigation, mechanical properties, tensile test, elongation, hardness, dielectric properties, conclusions, supporting information summary, acknowledgement, graphics complete with captions, tables, references, keywords, references and this table of contents.

Effects of fillers on the hydrogen uptake and volume expansion of acrylonitrile butadiene rubber composites exposed to high pressure hydrogen: -Property of polymeric materials for high pressure hydrogen devices (3)-

To develop sealing materials for high-pressure hydrogen devices, the effects of filler type and amount on the hydrogen uptake and volume expansion of rubber composites were evaluated up to 90 MPa. The amount of hydrogen in the rubber matrix and carbon black was elucidated using nuclear magnetic resonance, and the hydrogen elimination behavior of the composites was analyzed by thermal desorption analyses. As hydrogen physically adsorbed on carbon black, the hydrogen uptake of carbon black-filled composites increased. The hydrogen uptake of the composites filled with nonabsorbent silica was smaller, depending on the weight fraction of silica. The ratio of volume expansion to the amount of hydrogen in the matrix of carbon black-filled composites was suppressed by the reinforcement effect of carbon black, which did not expand with hydrogen uptake. The suppression of silica-filled composites was limited by the volume fraction of silica.

Significantly reinforced and long serviceable acrylonitrile butadiene rubber/graphitic carbon nitride composites for future industrial applications

The application of graphitic carbon nitride (g-C3N4) as non-black reinforcing filler is very little-known part in rubber technology. In the present study, g-C3N4 filled acrylonitrile butadiene rubber (NBR) composites were prepared by conventional two-roll milling process to investigate the influence of g-C3N4 on the mechanical and thermal performances of NBR formulations. NBR composite with 3 phr (parts per hundred parts of rubber) g-C3N4 presents considerably higher cure rate index, hardness, tensile strength, storage modulus and thermal stability than unfilled NBR composite. Also, the addition of g-C3N4 successfully enhances the thermal oxidative aging resistance and fuel consumption efficiency of NBR composites. Thus, g-C3N4 can be used in the near future as interesting filler for developing long serviceable NBR composites with good mechanical properties.

Characterization of barium titanate reinforced acrylonitrile butadiene rubber composites for flexible electronic applications: influences of barium titanate content

AbstractThe aim of this study was to develop high dielectric constant flexible polymers with a highly efficient and cost‐effective approach using acrylonitrile butadiene rubber (NBR) as the polymer matrix and barium titanate (BT) as the high dielectric constant filler. The BT powder was synthesized with a solid‐state reaction and was characterized using a particle size analyzer, XRD, SEM and Fourier transform infrared spectroscopy. NBR/BT composites were fabricated using an internal mixer with various BT loadings up to 160 phr. The influence of BT loading on the cure characteristics and mechanical, dynamic mechanical, thermal, dielectric and morphological properties was determined. The incorporation of BT in the NBR matrix shortened scorch time and increased delta torque. The mechanical properties, thermal stability and dielectric constant were greatly improved and increased with BT loading. The results suggest that the reinforcement effect was achieved due to strong hydrogen bonding or polar–polar interactions between NBR matrix and BT filler. This is further corroborated by the good dispersion of BT filler in the NBR matrix observed with SEM imaging. These findings can be applied to produce high‐performance dielectric elastomers. © 2020 Society of Industrial Chemistry

Synthesis of 2-Alkylbenzimidazole moiety as a novel antioxidant and its effect on physico-mechanical and electrical properties of acrylonitrile butadiene rubber

In the present work, 2-propyl-, and 2-heptyl-, 1H-benzo[d]imidazole were prepared by condensation reaction of o-phenylenediamine with n-butanoic acid and n-octanoic acid, respectively. The prepared products were characterized by FT-IR, 1H-NMR spectroscopy and melting point. These products were incorporated into acrylonitrile butadiene rubber (NBR) composites with two different fillers (Silica and High Abrasion Furnace carbon black HAF) as an antioxidant additive with different concentrations from 1up to 2 phr as a comparison with 2,2,4-trimethyl-1,2-dihydroquino-line (TMQ) as a traditional antioxidant. Their effects on the rheometric, physico-mechanical and electrical properties of NBR composites were evaluated. Thermo-oxidative aging was carried out for NBR composites and distribution of the prepared products observed by Scanning Electron Microscope (SEM).The results showed that the prepared products can act as highly efficient antioxidants in acrylonitrile butadiene rubber vulcanizates comparing with commercial antioxidant TMQ and revealed that there was enhancement in mechanical properties of NBR composites that containing the prepared products, as well. The results also illustrated that the optimum ratio from 2-alkylbenzimidazole incorporated into acrylonitrile butadiene rubber vulcanizates is 1.5 phr if compared with the same ratio from traditional antioxidant (TMQ).

Comparative Study of Bentonite Filled Acrylonitrile Butadiene Rubber and Carbon Black Filled NBR Composites Properties

This paper determines the potential of bentonite to replace the commonly used carbon black as filler in synthetic rubber composite product. Thus, the study made by comparing the results of curing, tensile thermal and morphological properties of bentonite and carbon black filled acrylonitrile butadiene rubber composites. The result of the tensile strength (TS), modulus at 100 % elongation (M100) and modulus at 300 % elongation (M300) for both bentonite (Bt) and carbon black (CB) filled NBR composites increased as the filler loading increased. The elongation at break (Eb) for Bt followed the same trend but not for NBR/CB composites. At similar filler loading, CB filled acrylonitrile butadiene rubber (NBR) composites demonstrated higher TS, M100, M300, and Eb compared to the Bt filled NBR composites. As the filler loading increased, the swelling percentage decreased for both types of fillers. However, at similar filler loading, the swelling percentage of CB filled NBR (NBR/CB) is lower than the Bt filled NBR (NBR/Bt). Scanning electron micrograph (SEM) of the tensile fractured surface of NBR/CB composites exhibits better filler dispersion and more tear lines compared to the NBR/Bt composites.

Thermoplastic Elastomer composite using Benzyl Chloride Treatment on Kenaf Core Powder Mixing with Polypropylene and Virgin Acrylonitrile Butadiene Rubber

The thermoplastic elastomer composite based tensile properties and morphology of kenaf core power (KCP) treated with benzoyl chloride filled polypropylene (PP)/virgin acrylonitrile butadiene rubber (vNBR) composites were aim and investigated. The composites with different KCP loading from 0 wt % to 30 wt % with constant PP and vNBR (70 wt% and 30 wt%) were prepared using heated two-roll mill by melt mixing at temperature of 180 °C. Tensile properties of composites which is tensile strength, Young’s Modulus and elongation at break were investigated. The morphology of filler and composites were investigated using scanning electron microscope (SEM). The result shown, the tensile strength, elongation at break and Young’s modulus of treated composites have higher by 4 - 14 %, 4 - 13 % and 0.5 - 3 % respectively compare untreated composite. These findings were supported by micrograph diagram from the morphological study. KCP filler treated with benzoyl chloride has improved the adhesion and gave strong interfacial bonding between KCP filler and PP/vNBRr matrices which results in good tensile strength of composites.

Penetrated hydrogen content and volume inflation in unfilled NBR exposed to high-pressure hydrogen–What are the characteristics of unfilled-NBR dominating them?

A series of unfilled acrylonitrile butadiene rubber (NBR) composites, which consists of several types of NBR with acrylonitrile (AN) monomer unit ratio (ΧAN) and sulfur or dicumyl peroxide (DPO) as a vulcanizer, were exposed to 90 MPa hydrogen gas to measure the saturated hydrogen content: C.H(0) and the volume change ratio when the sample volume is the maximum: VMAX/V0. The aim of this paper is to reveal the dominant characteristics for C.H(0) and VMAX/V0 of unfilled NBR composites. Mechanical properties, ΧAN, the molecular weight of the number average molecular weight between the effective crosslinks (Mef), the molecular weight between the chemical crosslink (MC) and the fractional free volume (FFV) were employed to examine the relationship between the characteristics and C.H(0) and VMAX/V0 of the NBR composites. Judging from the results of the comparisons of C.H(0) and VMAX/V0 with ΧAN, Mef, MC and FFV, it is revealed that C.H(0) and VMAX/V0 were dominantly correlate with FFV and MC, respectively.

7Effects on Thermal and Ablative Properties of Phenolic Resin (Novolac) Blended Acrylonitrile Butadiene Rubber

In this work we investigated the ablative response and thermal properties of phenolic resin (PR) blended acrylonitrile butadiene rubber (NBR) composites. PR was added to NBR in the proportion of 0, 5, 10, 20, 30, 40 and 50 phr by means of two-roll laboratory mill. PR remarkably improved ablation resistance and thermal properties of NBR/PR composite. The linear and mass ablation rates reduced to 21.3 % and 26.1 % respectively. The char content deposition increased from 0.19 to 26.8 %. Char layer produced by PR, obviously reduced the erosion rate of the NBR/PR composite relative to neat NBR (without PR). Detailed morphological studies of the composite and post-test (ablation) microstructure of char revealed that higher loading of PR in the rubber composite produced dense char layer firmly intact to the substrate. Furthermore, thermal stability of the composite improved by 22–23 oC, however, thermal conductivity of the composite slightly increased by 0.115 W/mK for 50 Phr of PR loading as compared to the neat.

Tribological properties of carbon nanotube as co-reinforcing additive in carbon black/acrylonitrile butadiene rubber composites for hydraulic seal applications

This work investigated the cure characteristic, physical mechanical properties, and tribology behavior of carbon black filled acrylonitrile butadiene rubber composites using multi-walled carbon nanotubes as co-reinforcing additive in various contents from 0, 3, 6, 9, and 15 parts per hundred rubbers. The physical and tribological behavior was also observed in large-scale piston driven hydraulic apparatus which was specially designed for seal applications. The results suggested that the modulus and hardness were found to increase after adding multi-walled carbon nanotube whereas the tensile and tear strength were not significantly affected. Adding multi-walled carbon nanotube was found to increase the bound rubber and crosslink density. For ball-on-disc tribo-testing, it was found that the coefficient of friction of the rubber composites decreased with multi-walled carbon nanotube content and the applied loads whereas the specific wear rate was more influenced by the applied loads used. Finally, under the large-scale piston driven hydraulic test apparatus in comparison with commercial grade rubber seals, it was found that the weight loss for the acrylonitrile butadiene rubber composites with multi-walled carbon nanotube was much lower than that without multi-walled carbon nanotube. The carbon black/acrylonitrile butadiene rubber composites with 9–12 parts per hundred rubbers multi-walled carbon nanotube were recommended as the most suitable for hydraulic seal applications.

Effects of bentonite loading on curing characteristics, tensile, thermal and morphological properties of bentonite-filled acrylonitrile butadiene rubber composites

In this paper, the effects of bentonite(Bt) loading on the performances of bentonite filled acrylonitrile butadiene rubber (NBR/Bt) composites were reported. The cure characteristics, tensile properties, thermal properties and morphology of NBR/Bt composites were studied. As the Bt loading was increased, the curing time (t90) and scorch time (ts2) were reduced until 30 phr of Bt loading and increased with further increasing of Bt loading afterwards. However, the minimum torque (ML) and maximum torque (MH) increased with increasing Bt loading. The increasing char residue and decomposition temperature indicated an improvement of thermal properties of NBR/Bt composites with increasing Bt loading. Furthermore, the tensile fractured surface morphology of the NBR/Bt composites has shown increasing crack propagation with more surface roughness. Hence, resulted a better tensile strength, elongation at break and tensile modulus compared to the pure NBR particularly up to 90 phr of Bt loading.

Effect of Zinc Oxide Modified Silica Particles on the Molecular Dynamics of Carboxylated Acrylonitrile-Butadiene Rubber Composites.

This work examines the molecular dynamics of carboxylated acrylonitrile-butadiene rubber crosslinked with zinc oxide modified silica particles. ZnO/SiO2 with the wide range of ZnO concentrations were used as both a crosslinking agent and filler. A series of thermal measurements were applied to the characterization of the samples: differential scanning calorimetry, dynamical mechanical thermal analysis, and dielectric relaxation spectroscopy. A complementary experimental technique, which is equilibrium swelling in solvents, confirms the presence of ionic crosslinks, which are created between zinc ions and the functional carboxyl groups of the rubber, within the structure of the vulcanizates. These interactions influenced not only the affinity of the vulcanizates to solvents, but also their dynamic mechanical and dielectric properties. In these investigations, the influence of concentration of ZnO on the surface of the ZnO/SiO2 on the properties of the vulcanizates are described.

Development of highly reinforced acrylonitrile butadiene rubber composites via controlled loading of sol-gel titania

Remarkable improvement in mechanical properties of acrylonitrile butadiene rubber (NBR) composites is achieved by incorporating nano-titania that is synthesised in solution of the raw rubber using titanium n-butoxide (TNB) as the titania precursor. This is achieved by designed and controlled incorporation of titania that resulted in very good dispersion of titania of nanometric dimension in rubber matrix and enhanced rubber-filler interaction. This sol-gel transformation is carried out under optimised reaction condition. Surface modification of titania by a silane coupling agent (bis-(3-triethoxysilylpropyl)-tetrasulfide, TESPT) causes further improvement in filler dispersion and composite properties when added in the reactive sol-gel system during in situ titania generation rather than it's external addition in the titania filled NBR during mixing and compounding. Thorough characterisation of the composites are done that encompasses a wide range of studies on thermal, morphological, mechanical, dielectric, dynamic mechanical, rheological and antifungal properties. The results are analysed on a comparative basis to investigate the effect of in situ incorporation and in situ surface modification of titania on the composite properties.

Thermal decomposition kinetics and mechanism of low-temperature hydrogenated acrylonitrile butadiene rubber composites with sodium methacrylate

Thermal decomposition processes and mechanism of low-temperature grade hydrogenated acrylonitrile butadiene rubber(LTG-HNBR) composites with sodium methacrylate(NaMAA) were investigated by thermogravimetric analysis(TGA) and Fourier transform infrared spectroscopy(FTIR) coupling technology in this article. The results of TGA demonstrate that the addition of NaMAA can enhance the thermal decomposition temperature of the rubber. Moreover, it was found that the composites spent more activation energies to decompose than pure rubber by the calculations of multiply heating rate method. Time-resolved FTIR spectra show that NaMAA affects the initial decomposition of the composites. But in the following process, the composites maintained a similar behavior to the matrix. During the decomposition, PNaMAA nanostructures, in-situ generated by NaMAA, helped reduce the diffusion speed of decomposition products and thus improved the thermal stability of the composites. We believe that these findings can provide some guides to direct the applications of LTG-HNBR composites with unsaturated metal methacrylates.

Dual Band Resonance in Tetragonal BaTiO3/NBR Composites for Microwave Absorption Applications

Tetragonal BaTiO3 bulk samples are prepared using the solid‐state route in conjunction with intermediate high‐temperature annealing steps. The (002) and (200) X‐ray diffraction peaks near 2Ɵ~45° and 310, 520, and 720 cm−1 characteristic vibrational modes in Raman spectroscopic measurements confirm the tetragonal crystallographic structure of BaTIO3 bulk samples. The 1100°C annealed BaTiO3 sample showed optimal tetragonality ~1.016 and the same is used for BaTiO3–acrylonitrile butadiene rubber (NBR) composites at different BaTiO3 loading fractions in parts per hundred (PHR). These BaTiO3/NBR composite systems exhibit dual band microwave resonance, widening the operating window for microwave absorption applications. Eighty PHR BaTiO3/NBR composite exhibits microwave reflection losses (RL) at 9.5 and 16.5 GHz with ~−9 and ~−18 dB reflection losses, respectively. The onset of dual band is attributed to the ferroelectric‐induced dipolar relaxation at 9.5 GHz and its second‐order resonance at 16.5 GHz in such composite systems.

Improved mechanical properties and thermal degradation of low-temperature hydrogenated acrylonitrile butadiene rubber composites with poly(sodium methacrylate) nanowires

Complex phase structures including a lot of poly(sodium methacrylate) nanowires improved the mechanical properties and thermal stability of LTG-HNBR composites.

Effect of cation-exchange bentonite on properties of acrylonitrile-butadiene rubber composites

The present work focuses on exchanging the sodium in Na-bentonite by single (Mg, Zn and Sr) and double (Zn–Mg, Mg–Sr and Zn–Sr) cations to induce the cation-exchange process. Different cation-exchange bentonites (CEBs) were used as reinforcing fillers with different loadings in acrylonitrile–butadiene rubber (NBR) composites. Curing characteristics, mechanical properties, morphology and swelling behaviour were determined. The study revealed that the performances of Mg bentonite and Mg–Sr bentonite were the best among the tested groups, while Sr bentonite showed the least performance, indicating that addition of Mg deteriorates the reinforcing efficiency of Sr. Moreover, it was observed that the preparation of some CEBs co-intercalated with a surfactant (cetyl trimethyl ammonium bromide (CTAB)) using cation-exchange process was done, and in this part there was a focus on the effect of CTAB surfactant content ratio (0.5CEC) on the CEBs and their influence on the properties of NBR composites.