Acrylonitrile Butadiene Rubber Blends Research Articles

Development of halloysite nanotubes reinforced chlorinated ethylene propylene diene monomer/chlorinated acrylonitrile butadiene rubber blends

Development of halloysite nanotubes reinforced chlorinated ethylene propylene diene monomer/chlorinated acrylonitrile butadiene rubber blends

Effect of Pre-Blending and Phase-Mixing Methods on Properties of Natural Rubber and Acrylonitrile Butadiene Rubber Blends Filled with Nano Silica Extracted from Rice Husk Ash

Properties of natural rubber (NR) and acrylonitrile butadiene rubber (NBR) blends are varied due to blending method. The literature is evident that the pre-blending and phase-mixing methods affect the properties of blends while opposite arguments are also available. Hence, that fact was interested to study using NR/NBR blends filled with rice husk ash nano silica (RHANS) having an average particle size of 50 nm - 100 nm with some micro-scale agglomerates. The structure of RHANS was proved using X-ray diffraction and Fourier transform infrared spectrophotometric analyses. Blends were prepared following both blending methods by varying NR to NBR ratio as 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0 while filling 25 parts per hundred parts of rubber of RHANS. The control was the ASTM formulation for oil seals. Vulcanization properties of blends showed acceptable levels with extended scorch and cure times and high torque properties. Blends indicated less tensile and tear strength compared to the control while showing acceptable hardness, compression set, and swelling properties. Overall, there is a possibility to use RHANS in NR/NBR blends and it was found that the blending method does not affect the properties of the NR/NBR blends.

In Situ Compatibilization of Polyamide 6/Carboxylated Acrylonitrile Butadiene Rubber Blends with Polyhedral Oligomeric Silsesquioxane

AbstractThe aim of the study is to prepare thermoplastic elastomer composites of polyamide (PA6) with carboxylated acrylonitrile butadiene rubber (XNBR), compatibilized with polyhedral oligomeric silsesquioxane with epoxy groups (POSS‐epoxy). The addition of POSS‐epoxy, particularly 3.5 phr, improved the specialty characteristics of the PA/XNBR thermoplastic‐elastomer blend. The PA/POSS/XNBR mainly showed a considerable improvement in the elastic torque. The in situ compatibilization is confirmed by density and oil swelling analyses. The structural property relationships of the vulcanized thermoplastic, measured by XRD, DSC and Raman spectroscopy, revealed there are changes in the chemical structure induced by the molecular interactions of PA‐POSS‐XNBR. The Raman spectra confirmed the presence of silane in the PA/XNBR blend. The crystallinity results obtained from the XRD spectra of the PA/XNBR blend are modified by the POSS‐epoxy, corroborating the oil swelling results.

Assessment of various nano‐clays in bromobutyl rubber hydrogenated acrylonitrile butadiene rubber blend for improved gas barrier applications

AbstractFor the past few decades, butyl rubber (IIR) and its derivatives have been used primarily in air barrier applications. Recently other synthetic rubbers like hydrogenated acrylonitrile butadiene rubber (HNBR) has attracted attention for its air barrier properties. A blend of brominated butyl rubber (BIIR) and HNBR can be a potential and novel material with improved technical features as well as excellent processing behavior. In this article, laponite (RD) and bentonite (MT) nano‐clays have been used to prepare BIIR‐HNBR blend based nanocomposites. A detailed investigation of nanocomposite morphology has been done using the transmission electron microscope results. The improvement in terms of mechanical and gas barrier properties of BIIR‐HNBR nano‐clay composites over BIIR‐carbon black composites have been explored in detail. The air impermeability of BIIR‐HNBR blends shows a 20% improvement compared to the reference composite. The results clearly demonstrate the usefulness and effectiveness of the material in gas barrier applications.

Enhancing mechanical and thermal properties of styrene-butadiene rubber/carboxylated acrylonitrile butadiene rubber blend by the usage of graphene oxide with diverse oxidation degrees

Graphene oxide (GO) with various oxidation degrees were prepared through a modified Hummer’s method by varying the dosage of oxidizing agent. Styrene-butadiene rubber (SBR)/carboxylated acrylonitrile butadiene rubber (XNBR)/GO nanocomposites were fabricated by aqueous-phase mixing of GO colloidal dispersion with SBR latex and a small loading of XNBR latex, followed by co-coagulation. Effects of GO oxidation degree on the morphology, structure, mechanical and thermal properties of nanocomposites were thoroughly investigated. The results showed that the mechanical strength of nanocomposites were enhanced with the increase of oxidation degree of GO. Especially, when the weight ratio of KMnO4 to graphite was 15/5, the tensile strength, tear strength and thermal conductivity of SBR/XNBR/GO filled with 3 phr (parts per hundred rubber) GO increased by 255.3%, 141.5% and 22.8%, respectively, compared to those of neat SBR/XNBR blend. In addition, the thermal stability and the solvent resistance of the nanocomposites were also improved significantly. This work suggested that GO with higher oxidation degree could effectively improve the properties of SBR/XNBR blend.

Comparison of Organoclay and PE-g-MA on Properties of Poly(Lactic Acid) and Acrylonitrile-Butadiene Rubber Blends

The effects of the montmorillonite clay surface modified with 0.5-5 wt% aminopropyltriethoxysilane and 15-35 wt% octadecylamine (Clay-ASO) and polyethylene-g-maleic anhydride (PE-g-MA) on morphology and mechanical properties of poly (lactic acid) (PLA)/acrylonitrile-butadiene rubber copolymer (NBR) blends were investigated and compared. The PLA/NBR blends and composites were prepared by melt mixing in an internal mixer and molded by compression molding. The ratio of PLA and NBR was 80/20 by weight and the Clay-ASO and PE-g-MA contents were 3, 5 and 7 phr. The morphology analysis showed that the addition of Clay-ASO and PE-g-MA at high content could improve the miscibility of PLA and NBR to be homogeneous blends due to the voids in the polymer matrix were decreased. The tensile properties showed Young’s modulus of the PLA/NBR/Clay-ASO composites was more than that of the PLA/NBR blends and Young’s modulus of composites increased with increasing Clay-ASO content, while the tensile strength and strain at break decreased with increasing Clay-ASO content. The incorporation of PE-g-MA 3 phr could improve the tensile strength, stress at break and strain at break of PLA/NBR blends.

Morphology and Mechanical Properties of Poly (Lactic Acid) and Acrylonitrile-Butadiene Rubber Blends with Organoclay

The effects of the montmorillonite clay surface modified with 25-30 wt% of methyl dihydroxyethyl hydrogenated tallow ammonium (Clay-MHA) on morphology and mechanical properties of poly(lactic acid) (PLA)/acrylonitrile-butadiene rubber copolymer (NBR)/Clay-MHA composites were investigated. The composites of blends of PLA/NBR with Clay-MHA were prepared by melt mixing in an internal mixer and molded by compression molding. The ratio of PLA and NBR was 80/20 by weight and the Clay-MHA content was 1, 3, 5 and 7 phr. The results showed Young’s modulus and stress at break of the composites increased with increasing Clay-MHA content. While the tensile strength and strain at break of the composites decreased with increasing Clay-MHA content. Scanning electron microscopy analysis showed that the addition of Clay-MHA could improve the miscibility of PLA and NBR to be homogeneous blends and the pore in polymer blends was disappeared.

Effect of blend ratio and testing rate on the adhesion properties of pressure-sensitive adhesives prepared from epoxidized natural rubber 25/acrylonitrile–butadiene rubber blend

The dependence of adhesion properties, that is, viscosity, tack, peel strength, and shear strength of epoxidized natural rubber (ENR 25)/acrylonitrile–butadiene rubber blend pressure-sensitive adhesive on blend ratio and testing rate was studied using coumarone–indene resin and toluene as tackifier and solvent, respectively. The rubber blend ratio was fixed at 0, 20, 40, 60, 80, and 100% of ENR 25 content. Four different thicknesses, that is, 30, 60, 90, and 120 μm, were used to coat the polyethylene terephthalate (PET) film. The viscosity of adhesive was determined by a Brookfield viscometer, whereas loop tack, peel strength, and shear strength were measured using a Lloyd adhesion tester operating at 10–60 cm/min. Results show that the viscosity of the adhesive decreases with increasing % ENR 25, whereas loop tack and peel strength pass through a maximum value at 20% ENR 25, an observation which is attributed to the optimum wettability and compatibility of adhesive at this optimum ENR 25 content. For the shear strength, it increases steadily with % ENR 25 due to the constant increase in cohesive strength. Adhesion property also increases with coating thickness and rate of testing at a fixed blend ratio.

Effect of sol–gel derived in situ silica on the morphology and mechanical behavior of natural rubber and acrylonitrile butadiene rubber blends

Silica particles were generated and grown in situ by sol–gel method into rubber blends comprised of natural rubber (NR) and acrylonitrile butadiene rubber (NBR) at various blend ratios. Silica formed into rubber matrix was amorphous in nature. Amount of in situ silica increased with increase in natural rubber proportion in the blends during the sol–gel process. Morphology studies showed that the generated in situ silica were nanoparticles of different shapes and sizes mostly grown into the NR phase of the blends. In situ silica filled NR/NBR blend composites showed improvement in the mechanical and dynamic mechanical behaviors in comparison to those of the unfilled and externally filled NR/NBR blend composites. For the NR/NBR blend at 40/60 composition, in particular, the improvement was appreciable where size and dispersion of the silica particles into the rubber matrix were found to be more uniform. Dynamic mechanical analysis revealed a strong rubber–in situ silica interaction as indicated by a positive shift of the glass transition temperature of both the rubber phases in the blends.

Preparation and characterization of thermoplastic polyurethane–urea and carboxylated acrylonitrile butadiene rubber blend nanocomposites

AbstractThis study deals with the preparation and characterization of novel thermoplastic polyurethane–urea (TPUU) and carboxylated acrylonitrile butadiene rubber (XNBR) blends. Blends of different compositions were prepared in tetrahydrofuran using a solution technique, following an ultra‐sonication. The chemical reaction between the two inherently immiscible blend phases was determined with the help of Fourier transform infrared‐attenuated total reflectance (FTIR‐ATR) spectroscopy and 1H‐nuclear magnetic resonance (1H‐NMR) spectroscopy. The identification of the new peaks in the FTIR‐ATR spectra corroborates the existence of chemical reaction between the carboxylic functional group of XNBR and the amide group of the TPUU. In addition, an increase in the network crosslink density of the blend investigated using 1H‐NMR spectroscopy further supports the occurrence of the chemical reaction between the XNBR and the TPUU. The scanning and transmission electron micrographs of the blend morphology show a uniform dispersion of the minor TPUU phase in the XNBR. Furthermore, the existence of a single glass transition peak also confirms the enhancement in the interfacial miscibility. Additionally, the incorporation of 5 wt % of organomodified montmorillonite nanoclay improves the mechanical properties to a considerable extent in comparison with the unfilled blend elastomeric material. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Processing and Characterization of Recycled Polypropylene and Acrylonitrile Butadiene Rubber Blends

In this paper investigation on thermoplastic elastomers (TPE) and thermoplastic vulcanizates (TPV) derived from waste polypropylene (WPP) of Municipal Solid Waste (MSW) and acrylonitrile-butadiene rubber (NBR) are reported. The WPP was segregated, cleaned, dried and melt processed with NBR at 180 °C in a Brabender Plasticorder at different blend ratios. TPV was prepared by dynamic vulcanization of the TPE with conventional sulfur accelerator curing system. The mechanical properties measured were found to decrease with increase in NBR proportion in the blend; however the dynamic vulcanization of the nitrile rubber phase enhanced the strength properties of the corresponding TPE. The crystallinity of the WPP reduced with increase in NBR ratio. The dynamic modulus decreased with nitrile rubber content in the TPE. Interestingly, the storage modulus of the TPV at higher rubber content enhanced significantly and damping characteristics increased sharply. The rheology studies reveal that the damping of the blend has been reduced with the addition of high storage modulus rubber at melt processing conditions and hence increased viscosity. The amorphous rubber content with higher storage modulus imparts higher viscosity for the polypropylene (PP) matrix at the processing temperature. The SEM study reveals that the dynamic vulcanization of the rubber phase in the blend caused a smoother and finer surface morphology.

Effects of dynamic vulcanization and glycidyl methacrylate on properties of recycled poly(vinyl chloride)/acrylonitrile butadiene rubber blends

Polymer blends with varying amounts of recycled poly(vinyl chloride) (PVCr) and acrylonitrile butadiene rubber (NBR) have been developed to produce thermoplastic elastomers (TPEs). The effects of dynamic vulcanization and glycidyl methacrylate (GMA) on mechanical and thermal properties, swelling index and morphology properties of the blends were studied. The blends were prepared at 150 °C using a rotor speed of 50 rpm for 11 min. It was found that dynamic cross-linking has enhanced the peak stress, stress at 100% elongation, thermal stability and swelling resistance of dynamically vulcanized PVCr/NBR+GMA blends compared to PVCr/NBR blends. The introduction of cross-links into the elastomer phase and better compatibility between PVCr and NBR are responsible for the enhancement of mechanical properties of dynamically vulcanized PVCr/NBR+GMA blends, as evidenced by the scanning electron microscopy (SEM) of extracted surfaces of the blends.

Niekonwencjonalne sieciowanie mieszanin chlorosulfonowanego polietylenu i karboksylowanego kauczuku butadienowo-akrylonitrylowego

Interpolymeric crosslinking of chlorosulfonated polyethylene/carboxylated acrylonitrile-butadiene rubber blends (CSM/XNBR) (Table 2) with MgO in the presence of stearic acid at temp. 433 K (160 oC) for 30 min has been investigated. Effect of CSM containing various amounts of chlorine bonded (Table 1) on the properties of CSM/XNBR blends was studied as well. Extent of crosslinking was estimated on the basis of determinations of vulcametric torque (L) (Fig. 1), equilibrium swelling (Qv) in selected solvents and sol fraction content (fraction soluble in 2-butanone - S) (Tables 3 and 5). It was found that CSM did not undergo crosslinking in given conditions while in the blend with XNBR the interpolymeric reaction of both elastomers occurred. It was confirmed by bounded chlorine values, S and IR analysis (Fig. 2, Table 4). It was observed that degree of CSM bonding with the network depends on its type and content in the blend. Tensile strength (TSb), elongation at break (Eb) temperature dependence of dynamic loss tangent (tgd) and storage modulus (E') (Fig. 3) were determined using dynamic mechano-thermal analysis (DMTA) of cured CSM/XNBR blends. There were found ionic interpolymeric bonds of structure ~C-CO-O-+Mg+-O-SO2-C~ in cured CSM/XNBR blend [equations (1)-(3)] which gave the blend high mechanical strength and act as chemical compatibilizer.

Effect of acrylic acid on the properties of recycled poly(vinyl chloride)/acrylonitrile–butadiene rubber blends

AbstractThe effect of acrylic acid (AAc) on the torque, stabilization torque, mechanical energy, swelling behavior, mechanical properties, thermal stability, and morphological characteristics of recycled poly(vinyl chloride)/acrylonitrile–butadiene rubber (PVCr/NBR) blends was studied. The blends were melt mixed at a temperature of 150°C and rotor speed of 50 rpm. AAc was used to improve the compatibility of PVCr/NBR blends. Virgin PVCv/NBR blends were prepared to provide a comparison. It was found that PVCr/NBR + AAc blends exhibit higher stabilization torque, mechanical energy, stress at peak, and stress at 100% elongation, but lower elongation at break and swelling index than those of PVCr/NBR and PVCv/NBR blends. SEM study of the tensile fracture surfaces of the blends indicated that the presence of AAc increased the interfacial interaction between PVCr and NBR phases, thus improving the compatibility between PVCr and NBR phases. However, thermal gravimetry analysis of the blends showed that the presence of AAc decreased the thermal stability of PVCr/NBR blends. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2181–2191, 2005