NBR Compounds Research Articles

Electrical and mechanical behaviors of rubber composites based on polar elastomers with incorporated Cu-based alloy

Dielectric elastomers with conducting inorganic fillers offer a wide range of uses, including capacitive energy storage, elastomer sensors, actuators, and many more. In this approach, low dielectric loss and high dielectric constant may be made possible by ternary composites that use metal alloy components as reinforcing fillers. Here, Cu-based alloy was added to acrylonitrile-butadiene rubber (NBR) to produce ternary rubber composites. Unfortunately, the Cu–Al–Zn alloy’s material incompatibility with the rubber matrix typically leads to phase separation, void formation, and particle aggregation, all of which have a dramatic negative impact on performance. Using 3-(trimethoxysilyl)propyl methacrylate as a coupling agent, Cu–Al–Zn alloy particles were uniformly dispersed onto the NBR rubber matrix through surface modification. By using scanning electron microscopy, the appropriate reinforcement of modified Cu-based alloy particles into NBR was carefully examined. The effect of modified Cu–Al–Zn alloy loading on the swelling behavior of the composite was also investigated. The findings show that the shape and dispersion state of modified Cu–Al–Zn alloy were important for the dielectric characteristics of the NBR compounds. By adding reinforced modified Cu-based alloy to the NBR matrix, mechanical characteristics were significantly improved. The uniform dispersion of modified Cu–Al–Zn alloy particles and strong interfacial compatibility with rubber matrix are the reasons for the outstanding performance of NBR composites, which suggests high-performance dielectric composite.

Unveiling the influence of end-capped acceptors modification on photovoltaic properties of non-fullerene fused ring compounds: a DFT/TD-DFT study.

Herein, unique A-D-A configuration-based molecules (NBD1-NBD7) were designed from the reference compound (NBR) by utilizing the end-capped acceptor modification approach. Various electron-withdrawing units -F, -Cl, -CN, -NO2, -CF3, -HSO3, and -COOCH3, were incorporated into terminals of reference compound to designed NBD1-NBD7, respectively. A theoretical investigation employing the density functional theory (DFT) and time-dependent DFT (TD-DFT) was performed at B3LYP/6-311G(d,p) level. To reveal diverse opto-electronic and photovoltaic properties, the frontier molecular orbitals (FMOs), absorption maxima (λ max), density of states (DOS), exciton binding energy (E b), open-circuit voltage (V oc) and transition density matrix (TDM) analyses were executed at the same functional. Moreover, the global reactivity parameters (GRPs) were calculated using the HOMO-LUMO energy gaps from the FMOs. Significant results were obtained for the designed molecules (NBD1-NBD7) as compared to NBR. They showed lesser energy band gaps (2.024-2.157 eV) as compared to the NBR reference (2.147 eV). The tailored molecules also demonstrated bathochromic shifts in the chloroform (671.087-717.164 nm) and gas phases (623.251-653.404 nm) as compared to NBR compound (674.189 and 626.178 nm, respectively). From the photovoltaic perspectives, they showed promising results (2.024-2.157 V). Furthermore, the existence of intramolecular charge transfer (ICT) in the designed compounds was depicted via their DOS and TDM graphical plots. Among all the investigated molecules, NBD4 was disclosed as the excellent candidate for solar cell applications owing to its favorable properties such as the least band gap (2.024 eV), red-shifted λ max in the chloroform (717.164 nm) and gas (653.404 nm) phases as well as the minimal E b (0.126 eV). This is due to the presence of highly electronegative -NO2 unit at the terminal of electron withdrawing acceptor moiety, which leads to increased conjugation and enhanced the intramolecular charge transfer (ICT) rate. The obtained insights suggested that the designed molecules could be considered as promising materials for potential applications in the realm of OSCs.

Coffee grounds as sustainable filler for bio‐based rubber composites

AbstractUsing biological/renewable resources as filler or modifier in both thermoplastics and rubbers has been of a great interest in order to reduce negative effects of traditional petroleum/natural gas based fillers. In this study, the main goal was the use of spent (waste) coffee grounds as a natural alternative filler to carbon black in acrylonitrile butadiene rubber (NBR) based compounds. Carbon black (CB) was partially replaced with fresh as well as spent coffee grounds (SCG) in NBR compound formulation. Stabilization effect of fresh coffee grounds was also investigated. Cure characteristics, physico‐mechanical, thermal, morphological, and dielectric properties of the bio‐based composites were tested and compared with the control (reference) compounds. Processability has been affected positively in the case of using coffee grounds thanks to the presence of triacyl groups in coffee. Up to 20% higher elongation at break values were measured when coffee is partially replaced with CB. Abrasion loss and oil resistance could be retained for coffee containing compounds. In conclusion, SCG were found to be a good natural alternative filler for bio‐based NBR composites without a significant change in material properties.Highlights Spent coffee grounds ‐ a sustainable filler in bio‐based NBR composites Both fresh and spent coffee grounds are successful stabilizers Physico‐mechanical, thermal, and dielectric properties are comparable

Characterization of the Mechanical, Biodegradation, and Morphological Properties of NBR/Biopolymer Blend, Integrated with a Risk Evaluation.

Biopolymer blends have attracted considerable attention in industrial applications due to their notable mechanical properties and biodegradability. This work delves into the innovative combination of butadiene-acrylonitrile (referred to as NBR) with a pectin-based biopolymer (NGP) at a 90:10 mass ratio through a detailed analysis employing mechanical characterization, Fourier transform infrared (FTIR) analysis, thermogravimetric analysis (TGA), and morphology studies using SEM. Additionally, biopolymer's biodegradability under aerobic and anaerobic conditions is tested. The study's findings underscore the superior tensile strength and elongation at break of the NGP/NBR blend in comparison to pure NBR, while also exhibiting a decrease in puncture resistance due to imperfect bonds at the particle-matrix interfaces, necessitating the use of a compatibilizer. In anaerobic conditions, evaluation of biodegradable properties reveals 2% and 12% biodegradability in NBR and NGP/NBR blend, respectively. The degradation properties were also aligned with TGA results highlighting a lower decomposition temperature for NGP. Additionally, this research integrates the application of a conditional value-at-risk (CVaR)-based analysis of the blend's tensile properties to evaluate the uncertainty impact in the experiment. Under risk, a significant enhancement in the tensile performance (by 80%) of the NGP/NBR blend was shown compared to pure NBR. Ultimately, the study shows that adding pectin to the NBR compound amplifies the overall performance of the biopolymer significantly under select criteria.

Effects of Peroxide and Sulfur Curing Systems on Physical and Mechanical Properties of Nitrile Rubber Composites: A Comparative Study.

This study compares the effect of sulfur and dicumyl peroxide (DCP) vulcanizing systems on the physical and mechanical properties of rubber compounds based on acrylonitrile butadiene rubber (NBR). NBR compounds cured by different amounts of DCP and NBR vulcanizates filled with various concentrations of carbon black (CB) and a constant amount of sulfur or DCP were prepared. The vulcanizates were characterized by tensile testing, dynamic mechanical thermal analysis (DMTA), and cross-link density determination. The tensile strength and Young's modulus were found to increase with the rising amount of DCP and CB, while elongation at break decreased. The samples vulcanized by the sulfur system and filled with CB show a substantial increase in tensile strength from 13.1 to 21.2 MPa. Higher storage modulus and glass transition temperature were observed with the increase in the amount of peroxide and filler, and consequently, the increase in cross-link density, indicating rigidity increase and lower molecular mobility. The changes in the physical and mechanical properties of the NBR vulcanizates were in correlation with the changes in solvent uptake and cross-link density.

Effect of a Natural Processing Aid on the Properties of Acrylonitrile-Butadiene Rubber: Study on Soybean Oil Fatty Acid from Seed Crop.

For the industrial production of rubber, one of the key ingredients is a processing aid. It not only facilitates the processability but also tunes the final properties of the resultant rubber. In general, for a polar rubber like acrylonitrile-butadiene rubber (NBR), the processing aids earning the most attention are synthesized from petroleum, such as dioctyl phthalate (DOP). However, due to their toxicity, many rubber chemists have tried to find alternative chemicals that are environmentally friendly and derived from a renewable resource. In this research, we investigated the effects of the soybean oil fatty acid (SBOFA), synthesized in house via hydrolysis of SBO, on the properties of NBR in comparison with DOP. Initially, it was found that the addition of SBOFA improved the flowability of the NBR compound, as indicated by the progressive decrease in the Mooney viscosity with increasing levels of SBOFA. The results from various techniques indicated that the crosslink density of the NBR vulcanizates passed through the maximum at the SBOFA loading of 4 phr. Upon loading SBOFA up to 4 phr, there was no significant deterioration in the mechanical strength of the SBOFA-plasticized NBR vulcanizates. Typically, the presence of SBOFA at 4 phr enhanced the thermal resistance of the NBR vulcanizate by shifting the thermal decomposition to a higher temperature. At a given loading, it was found that the SBOFA-plasticized NBR vulcanizate showed a comparable plasticizing efficiency and mechanical strength with the DOP-plasticized one. The result from this study shows that SBOFA is a good alternative sustainable eco-friendly processing aid to use for NBR.

Effect of composition ratios and mixing steps on properties of BR/NR/NBR blends and blends foam

This research is aimed to prepare foam from BR/NR/NBR blends which should integrate key property of these three rubbers. BR possesses high abrasion resistance but low tensile strength while NR possesses high tensile strength [1]. The addition of NBR was advantage for non-polar solvent resistance [2]. The effect of the mixing steps of rubber with vulcanizing additives on vulcanization of rubber and on mechanical properties and foaming of BR/NR/NBR were reported. The ratios of BR/NR/NBR were various as 60/20/20, 40/40/20 and 20/60/20. The vulcanizing additives used for rubber compounding were 5 phr ZnO, 2 phr stearic acid, 1.5 phr MBTS and 2 phr sulfur. The first part of the work was to study the effect of mixing step on rubber blends. Compounding system I was carried out by masticated BR, NR and NBR on a two-roll mill after that vulcanizing agent was added consecutively obtaining BR/NR/NBR rubber compounds with various rubber compositions. Rubber compounds were then characterized and vulcanized in order to investigate vulcanizate properties. In System II, three rubbers were mixed separately with required vulcanizing additives on the two-roll mill, obtaining BR, NR and NBR compound containing the same content of vulcanizing agent. Then the compounds were blended to obtain compound blended for the same blend ratios in System I. The blended rubber compounds were then characterized and vulcanized for their properties. In term of rubber blend foaming these two mixing systems were also used to compound the rubbers by addition foaming agent into the compound during mastication or blending of rubber on the two-roll mill. The results showed that mixing step affected the properties of rubber compound and vulcanizate in rubber blend. As various rubbers were mixed in different step resulting in different viscosity and hence affect foaming of rubber and subsequently properties of rubber foam.

Thermal characterization of the effect of fillers and ionic liquids on the vulcanization and properties of acrylonitrile\u2013butadiene elastomer

Different thermal analysis techniques were used to study the effect of fillers and ionic liquids (ILs) on the vulcanization process, thermal and dynamic mechanical properties of acrylonitrile–butadiene elastomer (NBR). The products of the studies were composites of NBR filled with hydrotalcite, nanosized silica or carbon black. ILs such as 1-butyl-1-methylpyrrolidinium (BMpyrrolBF4), 1-butyl-4-methylpyridinium (BMpyrBF4) or 1-butyl-1-methylpiperidinium (BMpipBF4) tetrafluoroborates were applied to improve the dispersion degree of the curatives and filler particles in the elastomer and to increase the efficiency of vulcanization. The differential scanning calorimetry results indicated that ILs reduced the vulcanization temperature of NBR compounds and increased the homogeneity of cross-link distribution in the elastomer network. NBRs filled with carbon black or silica exhibited similar thermal stabilities, whereas hydrotalcite reduced the temperature of thermal decomposition. The lowest mechanical loss factors were determined for vulcanizates filled with nanosized silica.

Effect of different carbon fillers on the properties of nitrile rubber composites

ABSTRACTIn this paper, the influence of carbon fillers with different structures such as carbon black (spherical), carbon nanofibers (fibrous), carbon nanotubes (tubular) and hydroxylated carbon nanotubes on the performance of acrylonitrile-butadiene rubber (NBR) composites have been investigated. The studies prove the significant role of the filler’s structure, surface characteristics and filler-filler interactions for composite reinforcement. As part of this study, the cure behaviour, crosslink density, thermal stability, electrical conductivity and mechanical properties of the filled NBR compounds were measured. Furthermore, scanning electron microscopy (SEM) as well as dibutylphthalate absorption (DBPA) measurements were carried out to determine the nature of the tested materials. It has turned out that the greatest reinforcing activity was exhibited by the carbon nanotubes (CNTs). However, all the tested carbon fillers significantly affected the performance of the nitrile rubber composites, which make them attractive additives for elastomer composites.

Effect of Simultaneous Use of Silica and Nanoclay in Rubber Compounds Based on Nitrile Rubber

The synergistic effect of simultaneous use of two reinforcing fillers in rubber compounds based on Acrylonitrile Butadiene Rubber (NBR) was investigated with mechanical and vulcanisation characteristics of the rubber compounds. The Wide-Angle X-ray Diffraction (WAXD) patterns showed that in hybrid compounds, no obvious peaks appeared. This indicated that the nanoclay was exfoliated. These results revealed that addition of the reinforcing filler, either nanoclay or silica, shortened the optimum cure time (t90) and also scorch time (ts1) of samples compared to that of pure NBR compound. In hybrid compounds, the reduction in optimum cure time and scorch time was higher than that of for silica-filled NBR or nanoclay-filled NBR compounds. This can be attributed to the synergistic effect between nanoclay and silica as two reinforcing agents in NBR compounds. Regardless the composition of the reinforcing filler, an increase of the relaxed storage modulus was observed, while the tand value was gradually decreased. For hybrid samples, the experimental values of dynamic modulus showed a positive deviation from the values obtained from the Modified Guth model. Hybrid compounds showed higher burst strength compared to silica or nanoclay filled NBR compounds.

KEMAMPUAN PROSES DAN KARAKTERISTIK VULKANISASI CAMPURAN NBR/EPDM

Blending of two rubbers can produce superior product properties. This study examines the process and cure characteristics of the NBR/EPDM blend. This study used several types of compatibilizer, i.e. methyl-methacrylate-butadiene-stirene (MBS), montmorillonite, and silica. Compatibilizer is used to get the homogeneous blend. NBR/EPDM compounds were done by two-roll mill. The mooney viscosity, rheology, and cure kinetics were studied with mooney viscometer and rheometer. It is known that the NBR/EPDM blends produce the compound with the process ability, curing time, and cure rate index better than NBR compound and EPDM compound separately. Montmorillonite as the compatibilizer produces compound with the process ability and cure rate index better than MBS and silica. Montmorillonite can be used as appropriate compatibilizer for the NBR/EPDM blend.

Influence of modifying agents of organoclay on the properties of nanocomposites based on acrylonitrile butadiene rubber

Solvent blending of organoclay (OC) in polystyrene in combination with melt mixing with acrylonitrile butadiene rubber (NBR) are applied to provide acrylonitrile butadiene rubber/clay nanocomposites. Clay structures based on the prepared 1,12 dibromododecylhydroxyuronium and bromo dodecyl hydroxyuronium as cationic surfactants were prepared. Colloidal suspension of each organoclay in toluene was mixed separately with polystyrene giving two types of polystyrene-organoclay composites. The prepared polystyrene-organoclay PS-OC composites were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The results indicate the formation of polystyrene-organoclay composites with intercalated and partial exfoliated structures. The rheometric study demonstrate an increase in minimum and maximum torques with an increase in cure rate index (i.e. faster scorch and cure times) for the PS-OC (6 phr) incorporated NBR compound compared to unfilled NBR. This effect is more significant with NBR/PS-OC1 composites in comparison to NBR/PS-OC2 composites at the same loading indicating the nanoreinforcement effect of clay on the mechanical properties of these composites. Compounds filled with PS-OC1 exhibit higher tensile strength, Young’s modulus and less elongation at break compared to those compounds filled with PS-OC2. The higher stiffness of PS-OC1/NBR composites reflects the enhancement in hardness of these compounds with respect to those containing PS-OC2. Further increasing of PS-OC loading results in a significant decrease of the properties. This is due to a possible agglomeration formation of PS-OC in rubber matrix. Furthermore, the results of reinforcement of polymers with nanosized particles indicate a promising application of the organoclay and nanocomposites that affords high performance materials.

Influence of melamine formaldehyde microsphere on the vulcanization kinetics and mechanical properties of nitrile butadiene rubber

The melamine formaldehyde (MF) microsphere/nitrile butadiene rubber (NBR) vulcanizates were prepared by adding MF into NBR through mechanical mixing, followed by a vulcanization process. The influences of MF on the vulcanization characteristics, vulcanization kinetics, and mechanical properties were investigated. The results showed that MF interacted with NBR through hydrogen bonds. In addition, parameter b calculated by the ratio of modulus and strains also demonstrated the strong interaction between MF and NBR. Adding MF into NBR would reduce the curing time of NBR compounds, and increase the curing rate, as well as the cross-linked density. The vulcanization kinetics of MF/NBR compounds could be simulated accurately by Ghoreishy’s model. The mechanical properties of MF/NBR increased with the incorporation of MF. The modulus at 100%, modulus at 300%, and tensile strength of NBR vulcanizates with 20 parts per hundred rubber MF had 155, 90, and 110% increment, respectively, compared with those of neat NBR. The MF also enhanced the tear strength of NBR by 80% with a rough tear-fractured surface of NBR recorded by scanning electron microscope.

Effect of carbon nanofibers on mechanical and electrical behaviors of acrylonitrile‐butadiene rubber composites

Recently, carbon nanofibers have become an innovative reinforcing filler that has drawn increased attention from researchers. In this work, the reinforcement of acrylonitrile butadiene rubber (NBR) with carbon nanofibers (CNFs) was studied to determine the potential of carbon nanofibers as reinforcing filler in rubber technology. Furthermore, the performance of NBR compounds filled with carbon nanofibers was compared with the composites containing carbon black characterized by spherical particle type. Filler dispersion in elastomer matrix plays an essential role in polymer reinforcement, so we also analyzed the influence of dispersing agents on the performance of NBR composites. We applied several types of dispersing agents: anionic, cationic, nonionic, and ionic liquids. The fillers were characterized by dibutylphtalate absorption analysis, aggregate size, and rheological properties of filler suspensions. The vulcanization kinetics of rubber compounds, crosslink density, mechanical properties, hysteresis, and conductive properties of vulcanizates were also investigated. Moreover, scanning electron microscopy images were used to determine the filler dispersion in the elastomer matrix. The incorporation of the carbon nanofibers has a superior influence on the tensile strength of NBR compared with the samples containing carbon black. It was observed that addition of studied dispersing agents affected the performance of NBR/CNF and NBR/carbon black materials. Especially, the application of nonylphenyl poly(ethylene glycol) ether and 1‐butyl‐3‐methylimidazolium tetrafluoroborate contributed to enhanced mechanical properties and electrical conductivity of NBR/CNF composites.

Engine Isolation Angular Mount with Different Types Elastomers

This article was focused on engine isolation elastomeric angular mounts. In ships, submarines heavy machinery is in continuous operations generate massive vibrations and noise. These vibrations and noise will transmit to sea water via machine foundation and will be a passive target for enemies. So it has to be reduced by providing isolation mounts or damping between machines and foundation or source and receiver. For this mounting systems should isolate engine vibrations caused by engine transmits forces in engine speed and prevent engine from shock excitation. This represents that dynamic stiffness and damping of the engine mount supposed to be frequency and amplitude reliant. So making of engine mount has been concerted on developing of frequency and amplitude properties. So different types of elastomeric shock and vibration mounts compounds are developed for two different hardness (45&55) all the mechanical properties ageing properties has been studied and compound with developed NBR, PU& CR compounds of same hardness. In all the cases PU elastomers based compounds are giving better results than NBR & CR. One angular mount is developed its static loads and deflection test at different rated loads has been carried out it gives satisfactory results

Effect of Cyclic Butylene Terephthalate Oligomer on the Properties of Styrene-Butadiene and Acrylonitrile-Butadiene Rubbers

In this work the effect of cyclic butylene terephthalate (CBT) was studied on the curing, rheological, morphological and mechanical properties of styrene butadiene rubber (SBR), oil extended styrene butadiene rubber (oSBR), acrylonitrile butadiene rubbers (NBR) with various acrylonitrile (AN) content and a carboxylated acrylonitrile butadiene rubber (XNBR). The effect of CBT on the oil resistance of the NBR and XNBR based compounds was also investigated. Viscosities of the uncured compounds were significantly decreased by CBT and it also acted as a semi-active filler, effectively reinforcing the tested rubbers, therefore it is suggested to be a bifunctional additive for tested rubbers. CBT also showed to have a positive effect on the oil resistance of NBR compounds.

Effects of methylene diphenyl diisocyanate on the physical, mechanical, and vulcanization properties of nitrile rubber

ABSTRACTIn this research, methylene diphenyl diisocyanate (MDI) was added to an acrylonitrile–butadiene rubber (NBR) compound as an additive, and its effects on the vulcanization of the rubber investigated. For this purpose, MDI was added at different concentrations (5, 10, and 20 phr) to the rubber compound. The rubber properties, including the rheometry and tensile strength, were investigated. Differential scanning calorimetry and swelling tests were used to assess the vulcanization mechanism and chemical reactions in the presence of MDI. Finally, Fourier transform infrared spectroscopy analysis was used to study the chemical structure of the NBR–MDI cured compounds. We found that MDI played a more important role than the additive in the NBR compound. It acted as a covulcanizing agent along with the sulfur groups. The 10 phr MDI content was found to be the optimum content for achieving the best NBR–MDI properties. This content increased the crosslinking density of the compound and decreased the swelling of NBR in toluene. We also found that MDI adsorbed the accelerator agents and sulfur groups, so it decreased the rate of vulcanization, especially at early ages. Furthermore, it reacted with NBR and produced strong urea (i.e., NHCONH) and thiourethane groups (i.e., SCONH), and this increased NBR's structural strength. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45200.

The physical and mechanical properties and cure characteristics of NBR/silica/MWCNT hybrid composites

The main objective of the present study was to investigate the synergistic effect of simultaneous use of two reinforcing fillers in rubber compounds based on acrylonitrile-butadiene copolymer (NBR). Silica was used as reinforcing filler in all samples and the loading content was 25 phr. 3 and 5 phr of multiwall carbon nanotubes (MWCNT) were used as second reinforcing filler in NBR/silica compounds. Melt mixing method was employed for compound preparation. The effects of carbon nanotube/silica hybrid filler on mechanical and vulcanization characteristics of the rubber compounds were investigated. These results revealed that addition of the reinforcing filler, either carbon nanotube or silica, shortened the optimum cure time (t 90) and also scorch time (t s1) of samples compared to that of pure NBR compound. In hybrid compounds, the reduction in optimum cure time and scorch time was higher than that of for silica-filled NBR or CNT-filled NBR compounds. This can be attributed to the synergistic effect between CNT and silica as two reinforcing agents in NBR compounds. Regardless the composition of the reinforcing filler, an increase of the relaxed storage modulus is observed, while the tan δ value is decreased steadily. The dynamic modulus reinforcement of nanocomposites was examined by the Guth Gold and Modified Guth Gold equations. For hybrid samples, the experimental values show a significant positive deviation from model predictions. According to the Barlow’s formula, hybrid compounds show higher burst strength compared to silica or CNT filled NBR compounds.

Effect of Peroxide and Organoclay on Thermal and Mechanical Properties of PLA in PLA/NBR Melted Blend

Acrylonitrile butadiene rubber, NBR, was added to poly(lactic acid), PLA, in order to improve the brittleness of PLA. NBR with the content of CN 34% was melt blended into PLA. This work was carried out in three parts. NBR with the content of 5, 10, 15, 20, 15, 20, 25 and 30% by weight was melt blended in an internal mixer. The second part, PLA, with the same contents as the first part, was melt blended with NBR compound (using dicumyl peroxide, DCP as vulcanizing agent) was dynamic vulcanized by melt blending with PLA in an internal mixer. Organic modified montmorillonite (OMMT), Cloisite 30B®, was added into NBR together with DCP. Cloisite 30B filled NBR compound was dynamic vulcanized with PLA by melt blending in the internal mixer. In the third part, the composition of NBR added in the blend was at 20, 25 and 30% by weight. The results showed phase separation between PLA and NBR. Tensile strength and tensile modulus were found decreased with the content of NBR whereas elongation at break was increased with NBR content, up to 10% NBR, then the elongation was decreased. Thermal stability of PLA was enhanced by the addition of NBR. For dynamic vulcanized NBR in PLA, the two phases was shown more compatible. Tensile elongation of PLA/dynamic vulcanized NBR blend was improved about 700-1100% compared to neat PLA. It was found that at 20% of NBR tensile elongation was increased about 1120%. Tensile strength and modulus of thermoplastic vulcanizate of PLA/NBR (PLA/NBR TPV) were found decreased 37% and 65% respectively, compared to neat PLA. The PLA/NBR TPV showed drawback in crystallization meanwhile thermal stability was very much improved. In order to improve mechanical properties of PLA/NBR TPV, OMMT was added. The results showed that modulus and tensile strength were enhanced whereas elongation at break was suffered due to the distribution of OMMT. It was shown in the form of aggregate rather than intercalated and exfoliated.

Exploiting the Plackett–Burman design to examine the formulation effect on curing characteristics of oil palm ash-filled acrylonitrile butadiene rubber compounds

The present paper is focused on exploiting Plackett–Burman design to examine the formulation effect of various chemical components content on the curing characteristics of oil palm ash (OPA)-filled acrylonitrile butadiene rubber (NBR) compound. The filled-NBR compound was prepared by conventional laboratory-sized two roll mill and cured using sulfuric system. Six independent variables such as content of zinc oxide, stearic acid, N-isopropyl-N′-phenyl-p-phenylenediamine, N-cyclohexyl-2-benzothiazole sulfenamide (CBS), sulfur, and even OPA filler were carried out to screen their significant effect on the curing characteristics of NBR compound. The scorch time, optimal cure time, minimum torque, and maximum torque were selected as a response. Results showed that the scorch time and the optimal cure time were significantly affected by CBS, whereas the minimum torque and maximum torque were significantly affected by OPA and sulfur, respectively, within the studied range. Among the chemical components under study, zinc oxide and stearic acid had the least effect on the curing properties of NBR compound. Analysis of variances for all factorial models demonstrated that the model was significant with P value <0.05 while the regularity (R 2) of all models was greater than 0.9. Lastly, the optimal chemical concentrations were predicted to acquire the optimal condition of the curing system for filled-NBR compound.