Effect Of Acrylonitrile Content Research Articles

Effects of acrylonitrile content and hydrogenation on fatigue behaviour of HNBR

AbstractThe influence of acrylonitrile (ACN) content and hydrogenation on the fatigue properties of HNBR is investigated. HNBR blends consist of different quantities of acrylonitrile (24, 36, and 44 wt%) and per cent hydrogenation (91%, 96%, and 99%), and a composite of two blends of HNBR with 24 and 44 wt% ACN for an average of 36 wt% . A comprehensive experimental campaign is carried out with fatigue life and crack propagation testing at 120°C. Afterwards, fatigue damage is analysed thanks to both optical and scanning electron microscopy. The results of the three experimental approaches demonstrate that HNBR with median ACN content (36 wt%) and median hydrogenation (96%) has the best fatigue resistance. In general, the fatigue resistance decreases in the following order: for ACN—36 to 44 to 24 wt%, and for hydrogenation—96% to 99% to 91%. The composite blend also has lower fatigue resistance than a regular HNBR blend.

Polylactide (PLA) and acrylonitrile butadiene rubber (NBR) blends: The effect of ACN content on morphology, compatibility and mechanical properties

In this study, attempts have been put to prepare toughened polylactide (PLA) through melt blending with acrylonitrile butadiene rubber (NBR) via melt mixing process. The influences of acrylonitrile (ACN) content on the compatibility, microstructure, tensile properties and impact resistance have been investigated. A matrix-dispersed droplet morphology was noted for all blend samples, and the rubber particle size decreased with decreasing ACN content of NBR. This droplet size, impact strength and elongation all corresponded well to the interfacial interaction that was evidenced by surface tension analysis and melt rheology. It was noted that the interfacial tension decreased with decrease in ACN content, accordingly, the results from both Cole-Cole curves and Han plots indicated high homogeneity of the PLA blend with NBR containing lower ACN contents. On the other hand, all blends exhibited very similar glass transition temperatures and crystallinity. It is concluded that extent of thermodynamic compatibility of PLA and NBR determines the improvement of toughness. Incorporation of only 10 wt% NBR resulted in dramatic improvements of elongation at break and impact strength of PLA and largely retained the high tensile strength of neat PLA.

Phase transition and aggregation behaviour of an UCST-type copolymer poly(acrylamide-co-acrylonitrile) in water: effect of acrylonitrile content, concentration in solution, copolymer chain length and presence of electrolyte.

An UCST-type copolymer of acrylamide (AAm) and acrylonitrile (AN) (poly(AAm-co-AN)) was prepared by reversible addition fragmentation chain transfer (RAFT) polymerization and its temperature-induced phase transition and aggregation behaviour studied by turbidimetry, static and dynamic light scattering, small angle neutron scattering (SANS) and cryo-transmission electron microscopy (cryo-TEM) measurements. The phase transition temperature was found to increase with increasing AN content in the copolymer, concentration of the solutions and copolymer chain length. A significant effect was observed onto the phase transition temperature by addition of different electrolytes into the copolymer solution. The copolymer chains were aggregated below the phase transition temperature and disaggregated above it. The size of the aggregates increases with increasing AN contents and concentration of the copolymer solutions below the phase transition temperature. The copolymer chains were expanded and weekly associated in solution above the phase transition temperature. A model is proposed to explain such association-aggregation behaviour of poly(AAm-co-AN) copolymers depending on AN contents and concentration of the copolymer solutions as a function of temperature.

Influences of Acrylonitrile (AN) Content in Styrene–Acrylonitrile (SAN) Copolymer on the Mechanical Property, Thermo-deformation Resistance, and Morphology of PVC–ASA–DOP Blends

Abstract In this work, PVC–ASA–DOP blends were prepared by melt blending ASA (acrylate–styrene–acrylonitrile) graft copolymer, poly(vinyl chloride) (PVC) resin with dioctyl phthalate (DOP). The effects of AN content on the property of the blends were investigated. The results showed that the mechanical property depended on AN content in the SAN copolymer, and PVC was immiscible with the SAN copolymer over the entire AN composition range. Thermo-deformation resistance was dependent on Tg and the storage modulus. From SEM, it was found that the morphology was consistent with the property.

Properties of ASA/SAN/NBR ternary blends: effect of AN content in NBR

Nitrile–butadiene rubbers (NBRs) with different acrylonitrile (AN) contents were used to toughen acrylonitrile–styrene–acrylic terpolymer/styrene–acrylonitrile copolymer (ASA/SAN) blends. The properties of the ASA/SAN/NBR ternary blends were investigated via dynamic mechanical analysis, heat distortion temperature, Fourier transform infrared spectroscopy and scanning electron microscopy (SEM). The effects of AN content in NBR on physical properties, heat resistance and morphology of the ternary blends were studied. Heat distortion temperature of the blends decreased with increasing AN content of NBR. The impact strength reached the maximum value when 20 phr NBR with 26 wt-%AN content was added. Images (SEM) were in accordance with results of mechanical properties.

The Effect of Acrylonitrile Content on the Abrasion Behavior of Unfilled Nitrile Rubber

Three unfilled nitrile rubber vulcanizates with different acrylonitrile contents (28%, 33%, and 40%) were prepared. The gravimetric wear rate of testing samples increased with increasing acrylonitrile contents. The cross-linking densities of rubbers were studied by the equilibrium swelling method. The measurement of the dissipated energy between tip and rubber surface was also carried out using tapping mode atomic force microscopy and the results suggest that the cross-linking density in local areas is primary responsible to the abrasion performance of unfilled nitrile rubber with reference to the polarity of polymeric matrix.

Effect of acrylonitrile content on compatibility and damping properties of hindered phenol AO-60/nitrile-butadiene rubber composites: molecular dynamics simulation

By combining molecular dynamics simulations with experiment, the effect of acrylonitrile content on the compatibility and damping properties were investigated in the AO-60/nitrile-butadiene rubber composites.

Effects of acrylonitrile content and molecular weight on the scratch behavior of styrene‐acrylonitrile random copolymers

AbstractFundamental understanding of the scratch behavior of styrene‐acrylonitrile (SAN) random copolymers with variation in acrylonitrile (AN) content and molecular weight (MW) is pursued using the methodology outlined in ASTM D7027‐05/ISO 19252:08. Two sets of SAN model systems are employed: One that varies the AN content with similar MW and another that varies the MW at the same AN content. Key scratch damage mechanisms (scratch groove formation, periodic micro‐cracking, and plowing) are identified and correlated with the compressive and tensile properties of the SAN systems. Scratch visibility is analyzed through the use of a commercial software package. A fundamental structure–property relationship of SAN scratch behavior is proposed by the fact that increasing the AN content or the MW can have a positive effect on increasing the scratch resistance of SAN as it improves its tensile strength and ductility. The implication of material properties and their effect on polymer scratch behavior is discussed. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981MPa), tensile strength (maximally 27.7MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94×1028m−3), density (maximally 1.16gcm−3), and tear strength (11.2kNm−1), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

Effects of acrylonitrile content on the coordination crosslinking reaction between acrylonitrile–butadiene rubber and copper sulfate

The effects of acrylonitrile content in acrylonitrile–butadiene rubber (NBR) on coordination crosslinking reaction were investigated in the system of NBR filled with copper sulfate (CuSO 4) particles by means of dynamic mechanical analysis (DMA), equilibrium swelling method, differential scanning calorimetry (DSC) and tensile test. DMA analysis showed that higher the acrylonitrile content in NBR, higher the storage modulus of the CuSO 4/NBR composite. The results of equilibrium swelling method and DSC displayed the crosslink density and glass transition temperature of CuSO 4/NBR composites increased with increment of the acrylonitrile content, respectively. And the tensile strength of CuSO 4/NBR composites became strong with the acrylonitrile content rising. All the results showed that increase acrylonitrile content of NBR could accelerate the coordination crosslinking reaction between NBR and CuSO 4. The tensile strength of CuSO 4/NBR composites increased with increment of acrylonitrile content, which was attributed to increased interfacial contact area and enhanced interfacial adhesion between CuSO 4 and NBR.

Effect of acrylonitrile content on the glass transition temperature and melt index of PVC/SAN blends

PVC and SAN are often mixed to compensate for the disadvantages of each polymer. Miscibility and thermal stability of PVC/SAN blend were investigated in this study by blending SAN polymer having 20, 24, 28, 32 % of acrylonitrile contents. Two polymers were mixed using a melt blending method with a single screw extruder. DSC them ogram was used to evaluate miscibility of the two polymers. SAN having 24 % of acrylonitrile showed the best miscibility with PVC. In order to evaluate degradation behavior, blended polymer was heat treated in DSC furnace and glass transition temperature was measured consecutively. Glass transition temperature increased continuously with annealing time due to degradation and cross-linking of polymer chains. Melt index of blended polymer was always higher than that of PVC.

Styrene-acrylonitrile (SAN) layered silicate nanocomposites prepared by melt compounding

Poly(styrene-co-acrylonitrile) (SAN) nanocomposites were successfully made by melt compounding and exhibited improved thermal stability and reduced flammability. The organoclays used in these nanocomposites were based upon fluorinated synthetic mica (FSM) or montmorillonite (MMT). Four different organic treatments were used on the clay surface to study the effect of organic treatment on clay dispersion: dimethyl, bis(hydrogenated tallow) ammonium (DMHTA), methyl tallow bis-2-hydroxyethyl ammonium (MTBHA), triphenyl, n-hexadecyl phosphonium (TPHDP), and 1,2-dimethyl-3- n-hexadecyl imidazolium (DMHDI). Along with studying the effect of clay organic treatment on the nanocomposite formation and flammability, the effect of acrylonitrile content in the SAN on nanocomposite formation and flammability was also studied. The overall findings suggest that dispersion of clay into SAN is rather facile, but certain combinations of organic treatment and clay type resulted in microcomposites rather than nanocomposites. Flammability of these materials was measured by pulse-combustion flow calorimetry (PCFC), also known as micro-cone calorimetry.

Effect of acrylonitrile content on physical properties of electron beam irradiated acrylonitrile–butadiene rubber

The effect of acrylonitrile content on the physical properties of acrylonitrile–butadiene rubber (NBR) under electron beam induced vulcanization was studied. Diethylene glycol dimethacrylate (2G) and trimethylol propane trimethacrylate (TMPT) were used as polyfunctional monomers (containing two or more polymerizable CC double bonds in a molecule, PFMs) to lower the irradiation dose. The effect of acrylonitrile content (AN) on physical properties was pronounced only at low doses where the crosslink densities were not too high. The crosslink density in the polymer matrix is affected by the nature of polyfunctional monomers (PFMs) and acrylonitrile content of NBR. In radiation vulcanized NBR, the crosslink density in the matrix is increased by increasing AN content with corresponding decrease in swelling.

Morphology and physical properties of SAN/NBR blends: The effect of AN content in NBR

Poly(styrene-co-acrylonitrile) (SAN), of which the content of acrylonitrile (AN) repeating unit is 32 wt % (SAN32), was blended with poly(butadiene-co-acrylonitrile) (NBR). The effects of AN repeating unit content in NBR on the miscibility, morphology, and physical properties of SAN32/NBR (70/30 by weight) blends were studied. Differential scanning calorimetry and the morphology observed by transmission electron microscopy showed that the miscibility between SAN32 and NBR was increased as the AN content in NBR was increased up to 50 wt %. The impact strength and some other mechanical properties of the blends had the maximum value when the AN content in NBR was 34 wt %. In the measurement of viscoelasticity at melt state, SAN32/NBR blends showed yield behavior at low shear rate, and this behavior was most evident when the AN content in NBR was 34 wt %.

Effects of acrylonitrile content on PC/ABS alloy systems with a flame retardant

To investigate the effect of a flame retardant on PC/ABS alloy systems, a reactive-type brominated epoxy resin was used as a flame retardant, and mixed with PC/ABS at various amount using a twin-screw extruder. The rheological, morphologi- cal, mechanical, and thermal properties were investigated as a function of acrylonitrile (AN) content in ABS. The shear viscosity of the PC/ABS blend increased as the AN content in ABS increased. Temperature drastically affected the shear viscosity in the ABS matrix, but not as much in the PC matrix. A blend of PC 50% containing AN 22% is suitable to process because its shear viscosity is low in the high shear rate region and its mechanical properties drastically increase in the beginning of the PC matrix. In addition, gradual increases of heat distortion temperature were observed in the entire range of the PC content. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 417- 423, 2000

Morphology and physical properties of SAN/NBR blends: The effect of AN content and melt viscosity of SAN

To study the effect of dispersed poly(butadiene-co-acrylonitrile) (NBR) rubber size on the physical properties of poly(styrene-co-acrylonitrile) (SAN)/NBR blends, SANs with various melt viscosities and acrylonitrile (AN) contents were examined. The dispersed size of NBR, whose AN content is 30 wt %, was reduced as the melt viscosity of the SAN matrix was increased or as the AN content of the SAN matrix was reduced in the range of 19–32 wt %. As the melt viscosity of the SAN matrix was increased, the damping peak of the NBR phase moved to a higher temperature, and as the AN content of SAN was reduced, the damping peak of the SAN phase moved to a lower temperature. Higher values of impact strength and elongation at break and reduced yield behavior at a low shear rate were observed at a finer dispersion of NBR. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 935–941, 1999

Effect of acrylonitrile content on the delamination toughness of PC/SAN microlayers

The effect of acrylonitrile (AN) content on the adhesion of poly(styrene-co-acrylonitrile) (SAN) to polycarbonate (PC) was examined by measuring the delamination toughness of PC/SAN microlayers in the T-peel test. Experiments were carried out on microlayers with thin SAN layers, to ensure that delamination would occur predominantly by an interfacial mechanism, and with PC layers that were thick enough to prevent the delamination crack from tearing through the PC. Layer thicknesses of approximately 4.5 μm/0.5 μm (PC/SAN) gave satisfactory results. A broad maximum in the interfacial toughness occurred at about 20% AN. When microlayers with thicker SAN layers were tested, only SAN compositions with 15–25% AN crazed. This increased the delamination toughness and greatly exaggerated the maximum at 20% AN. Crazing only occurred if the interfacial toughness of PC-SAN exceeded the SAN crazing condition. When the crazing condition, which increased linearly with AN content, was overlayed with the interfacial toughness, the intersections correctly predicted the AN content for transitions in failure mode.

Effect of acrylonitrile content on the toughness of ABS materials

Styrene/acrylonitrile (SAN) copolymers were toughened by addition of several SAN emulsion grafted rubbers. The main variables of the study included the AN content of the SAN graft (14.2–37.5%) and the AN content of the SAN matrix (14.7–40%). The aim was to develop general principles underlying the properties of rubber toughened SAN or ABS materials. Rubber-matrix adhesion, state of rubber particle dispersion and the inherent ductility of matrix polymer were evaluated, and the trends found in the mechanical behaviour of the blends are reasonably well explained by these three factors. The concept of inherent ductility, in particular, is effectively utilized and its importance in the ultimate properties of rubber toughened SAN is emphasized.