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The effects of processing conditions were studied for ternary polymer blends based on polyamide 6 (PA6)، polycarbonate (PC) and Acrylonitrile-butadiene rubber (NBR). The ternary blends were accumulated at fixed compositions (PA6/ PC/NBR: 80/10 /10 wt%) using counter-rotating twin-screw extruder under three levels of blending sequence، die temperature، and screw speed. The experimental design was fulfilled by using Taguchi experimental analysis and the field emission scanning electron microscopy (FESEM) micrographs were used to investigate the microstructure. The mechanical properties such as tensile properties (Young''s modulus and yield stress) and impact strength were highly influenced by processing conditions and the mean effects of each factor were calculated to investigate their role on mechanical properties of the blends.

The effect of nanoclay (Cloisite® 15A) was studied in relation to the flow behavior، mechanical and thermal properties of polypropylene/maleic anhydride-g- (styrene-ethylene-butylene-styrene) triblock copolymer (PP/SEBS(15%) -g-MA) blend. In this regard، the composites based on the blend and various amounts of nanoclay (1،3،5 wt%) were melt compounded using an internal mixer at the temperature of 190°C، rotor speed of 75rpm for 12min. The prepared samples were compression molded in a hot-press machine under the conditions of 190°C، 31 MPa pressure for 9 min to obtain the sheets in various thicknesses. The sheets were then cooled to ambient temperature with cooling water at the rate of 1. 5°C. s-1. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to study the structure and morphology of the samples. In addition، the mechanical and thermal properties were determined by standard methods. The results of X-ray diffraction and transmission electron photographs confirmed both exfoliated and intercalated structures in the prepared samples. There were balanced strength/toughness properties in all the prepared nanocomposites by addition of both SEBS-g-MA and clay simultaneously. The measurement of rheological properties showed that as the shear rate increased، the apparent viscosity of the samples decreased (shear thinning behavior). Gradual increase in incorporation of nanoclay also decreased the melt flow index (MFI) values. In addition، increases in nanoclay content had an insignificant effect on the thermal behavior and in that respect there were slight increases in degree of crystallinity، heat deflection temperature (HDT) as well as Vicat softening point by slight increase in temperatureThe effect of nanoclay (Cloisite® 15A) was studied in relation to the flow behavior، mechanical and thermal properties of polypropylene/maleic anhydride-g- (styrene-ethylene-butylene-styrene) triblock copolymer (PP/SEBS(15%) -g-MA) blend. In this regard، the composites based on the blend and various amounts of nanoclay (1،3،5 wt%) were melt compounded using an internal mixer at the temperature of 190°C، rotor speed of 75rpm for 12min. The prepared samples were compression molded in a hot-press machine under the conditions of 190°C، 31 MPa pressure for 9 min to obtain the sheets in various thicknesses. The sheets were then cooled to ambient temperature with cooling water at the rate of 1. 5°C. s-1. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to study the structure and morphology of the samples. In addition، the mechanical and thermal properties were determined by standard methods. The results of X-ray diffraction and transmission electron photographs confirmed both exfoliated and intercalated structures in the prepared samples. There were balanced strength/toughness properties in all the prepared nanocomposites by addition of both SEBS-g-MA and clay simultaneously. The measurement of rheological properties showed that as the shear rate increased، the apparent viscosity of the samples decreased (shear thinning behavior). Gradual increase in incorporation of nanoclay also decreased the melt flow index (MFI) values. In addition، increases in nanoclay content had an insignificant effect on the thermal behavior and in that respect there were slight increases in degree of crystallinity، heat deflection temperature (HDT) as well as Vicat softening point by slight increase in temperature. The aim of this work is to study effect of nanoclay (Cloisite® 15A) on the flow behavior، mechanical and thermal properties of polypropylene/maleic anhydride grafted- (styrene-ethylene-butylene- styrene) triblock copolymer (PP/15%SEBS-g-MA) blend. In this regard، the composites based on the blend and various amounts of nanoclay (1،3،5 wt. %) were melt compounded using an internal mixer at the temperature of 190oC، rotor speed of 75rpm for 12min. The prepared samples were then compression molded in a hot-press machine under the conditions of 190°C، 31 MPa pressure، for 9 min to obtain the sheets in various thicknesses. Afterwards، the plates were cooled to ambient temperature with cooling water at the rate of 1. 5oC. s-1. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to study the structure and morphology of the samples. In addition، the mechanical and thermal properties were carried out by means of the standard methods. The results of X-ray diffraction and transmission electron photographs confirm both exfoliated and intercalated structures in the prepared samples. There is balanced strength/toughness properties in all the prepared nanocomposites via addition both SEBS-g-MA and clay simultaneously. The measurement of rheological properties show that as the shear rate increases، the apparent viscosity of the samples decreases (shear thinning behavior). Incorporation of nanoclay and increasing its content also decreases the melt flow index (MFI) values. In addition، increase in the nanoclay content have the insignificant effect on the thermal behavior so that slight increase in crystallinity temperature/degree، heat deflection temperature (HDT) as well as vicat softening point are obtained.

Ternary polymer blends based on polyamide 6 (PA6)/polycarbonate (PC)/acrylonitrile-butadiene rubber (NBR) were prepared at fixed compositions using a twin-screw extruder. The ternary blends mixed at 240 ̊C of die temperature and 130 rpm of screw speed at different levels of blending sequence (B.S1-B.S2-B.S3). In B.S1, the blending sequence, all components were extruded simultaneously but in B.S2 and B.S3 blending sequences, the produced master batch of PC+NBR and PA6+PC were added to the other absent phase. The mechanical properties of ternary blends were influenced by mixing method and the results of mechanical testing were confirmed using the field emission scanning electron microscopy (FESEM) micrographs.

Nanocomposites based on butadiene rubber (BR)، (0، 3، 5 and 7 phr) organoclay (Cloisite 15A) and (0، 10، 20، 30، 40 phr) powder coating wastes، i. e.، epoxypolyester hybrid (EPH) were prepared using a laboratory-scale internal mixer in order to study the effect of organoclay and EPH content on the mechanical and morphological properties of the nanocomposite samples. Cure characteristics of the prepared compounds including optimum cure time (t90) and scorch time (t5) depicted a decrease in both mentioned factors with increasing nanoclay content and EPH loading. Intercalation of elastomer chains into the silicate layers was determined by d-spacing values calculated according to the results of X-ray diffraction (XRD) patterns. X-ray diffraction (XRD) results reveal the intercalation of elastomer chains into the clay galleries. This phenomenon was also confirmed according to the scanning electron microscopy (SEM) micrographs and mechanical properties of the nanocomposite samples which were observed to be improved with addition of nanoclay and EPH content.

Nanocomposite samples based on elastomer blends of butyl rubber (IIR) and ethylene propylene diene monomer (EPDM) were prepared using a laboratory scale two-roll mill in order to study the effect of Cloisite 15A organoclay content (i.e., 1, 3, 5 and 7 wt%) on the mechanical and morphological properties of IIR/EPDM/Cloisite 15A nanocomposites compared to the unflled EPDM/IIR blends. Rheometer (RPA), X-ray diffraction (XRD) and scanning electron microscope (SEM) were utilized for relevant characterization of cure behavior and microstructural properties of the prepared samples. Cure characteristics of the prepared compounds including optimum cure time (t90) and scorch time (t5), depicted a decrease in these two parameters with increasing nanoclay content; where the cure time was prolonged with EPDM increasing content. In fact, nanoclay not only acts as a reinforcing agent in nanocomposites but also accelerates the cure process of IIR/EPDM elastomer compounds. Intercalation of elastomer chains into the organoclay silicate layers was determined by d-spacing values calculated according to the results of X-ray diffraction patterns. XRD results of all the nanocomposites samples prepared here showed a leftward shift towards lower diffraction angles in the organoclay characteristic peak, indicating an increase in the d-spacing values compared to the pure organoclay which emphasizes the intercalation of elastomer chains into the clay galleries. This phenomenon was also confrmed according to the direct observation of the cryogenically fracture surfaces of the samples by SEM micrographs depicting a combination of intercalated and exfoliated microstructures. However, there appeared incrementally slowed down rate in higher clay contents. With addition of nanoclay, mechanical properties of the nanocomposite samples including hardness, fatigue strength, tensile modulus and tensile strength were observed to be improved. Elongation-at-break and resilience of the nanocomposites were decreased as expected.

The organo-metal salt of aluminum triacrylate (ALTA) with a general formula of (CH2=CHCOO)3Al was synthesized as a reactive fller for elastomers through a two-step synthetic procedure. Fourier transform-infrared spectroscopy (FTIR), DSC and DTA were employed for ALTA analysis and to study its cure characteristics. In this research, two composites based on ethylene propylene diene monomer rubber (EPDM) with two types of reactive fllers of modifed organoclay and ALTA were prepared by a laboratory two-roll mill. The types and different ratios of organoclay and ALTA on curing characteristics, mechanical properties such as tensile properties, hardness, and abrasion resistance were studied. The increase in fller content of both composites led to the incremental increase in tensile strength, modulus, hardness, elongation-at-break and also the incremental increase in abrasion resistance of both composites. The improvement in reinforcing properties of ALTA in comparison with nanoclay is attributed to homopolymerization and graft copolymerization of ALTA at the same time during curing of the EPDM composites by peroxide. Making such additives may be taken as an effective action to achieve more durable and cheaper way to reinforce elastomers.

Mixing conditions of NBR/PVC nanocomposites such as mixing temperature,rotor speed and mixing time are determining parameters in rheological,mechanical and morphological properties of the compound. Three levelswere chosen for each parameter using Design Expert software via Box-Behnkenmethod. The nanocomposite samples were melt-mixed in Brabender internal mixer. Theeffect of various mixing parameters such as mixing temperature, rotor speed and mixingtime was investigated by stress-strain and rheological curves. The TPE nanocompositeswere characterized by X-ray diffraction (XRD), transmission electronmicroscopy (TEM), dynamic mechanical thermal analysis (DMTA), and mechanicalproperties.

Acrylonitrile butadiene rubber (NBR) composites are prepared from wastenylon 66 short fiber using a two-roll mill mixer. The effects of fiber contentand bonding agent on the mechanical and morphological properties of thecomposites are studied. The curing characteristics of the composites have been studiedby using cure rheometer. The cure and scorch time of the composites decrease whilecure rate is increased when short fiber content is increased. The mechanical propertiesof the composites show improvement in both longitudinal and transverse directions withincrease in short fiber content. The adhesion between the fiber and rubber is enhancedby using a dry bonding system consisting of resorcinol, hexamethylenetetramine andhydrated silica (HRH). The swelling behavior of the composites in N,N-dimethylformamideis tested to find the effect of bonding agent on adhesion strength of the matrixand fibers. Fracture surface morphology of composites is studied by scanning electronmicroscopy. The restriction to swelling is higher for composites containing bondingagent, especially, in the longitudinal direction. The morphology of the fracture surfaceshows less fiber pull out when the bonding agent is introduced

Afinite element model is developed for simulation of the curing process ofa thick axisymmetric rubber article reinforced by metal plates during themolding and cooling stages. The model consists of the heat transfer equationand a newly developed kinetics model for the determination of the state of curein the rubber. The latter is based on the modification of the well-known Kamal-Sourour model. The thermal contact of the rubber with metallic surfaces (inserts andmolds) and the variation of the thermal properties (conductivity and specific heat)with temperature and state-of-cure are taken into consideration. The ABAQUS codeis used in conjunction with an in-house developed user subroutine to solve the governingequations. Having compared temperature profile and variation of the state-ofcurewith experimentally measured data, the accuracy and applicability of the modelis confirmed. It is also shown that this model can be successfully used for the optimizationof curing process which gives rise to reduction of the molding time.

Elastomer compound based on NR/BR was prepared using different kinds of nano-ZnO and ZnO. The effect of zinc oxide as an activator of sulfur cure on the mechanical and morphological properties of the compound was studied. The result of the mechanical properties showed that the tensile strength, elongation-at-break, resilience, and abrasion resistance of the compound prepared by ZnO (4 phr) are equal to the compounds using nano-ZnO (Iran, 1 phr) and nano-Zno (China, 2 phr). The cure time of the compound with nano-Zno is less than that of the compound using ZnO while the scorch time of those compounds is the same. The SEM of the samples showed that the particle size of nano-ZnO (Iran) is smaller than that of ZnO and nano-Zno (China) and also uniformly dispersed.