Mehdi Entezam  Danial Nozari  Mohammad Mirjalili  Hossein Ali Khonakdar 《Polymer-Plastics Technology and Engineering》2015,54(15):1571-1584

Correlation of rheological response with microstructure and also the tensile mechanical properties of nanoclay-filled polyethylene/ethylene vinyl acetate blends were studied. From transmission electron microscopy observations, the same clay localization within polyethylene- and ethylene vinyl acetate-rich blends was revealed. However, a better clay dispersion in the ethylene vinyl acetate-rich blend was found by analyzing the changes in the linear viscoelastic rheological properties discussed by the fractional Zener model and the power law expression. The clay influences on the tensile properties of polyethylene- and ethylene vinyl acetate-rich blends were in good agreement with its microstructure, implied by the rheological studies.  相似文献   

    

Mohammad Reza Saeb  Hossein Ali Khonakdar  Seyed Hassan Jafari  Hadi Rastin  Udo Wagenknecht  Gert Heinrich 《Polymer-Plastics Technology and Engineering》2015,54(2):223-232

We quantified interfacial adhesion in ternary blends with matrix/shell/core microstructure based on mechanical properties assessments. Various HDPE-based ternary blends containing PA-6/EVOH core/shell droplets were prepared by changing composition and processing temperature. The theoretical predictions of tensile properties were compared with experimental data; thereby considerable shift in experimental modulus from lower to upper limit observed over a 10°C increase in melting temperature. This confirmed the impact of blending temperature on matching the predicted values with experimental data. The meaningful trend observed in tensile characteristics of ternary blends simply gives an understanding of interfacial adhesion degree in ternary blend showing matrix/shell/core microstructure.  相似文献   

    

Mohammad Hossein Keshavarz  Karim Esmailpour  Mehdi Zamani  Akbar Gholami Roknabadi 《Propellants, Explosives, Pyrotechnics》2015,40(6):886-891

The M06‐2X/6‐311G(d,p) and B3LYP/6‐311G(d,p) density functional methods and electrostatic potential analysis were used for calculation of enthalpy of sublimation, crystal density and enthalpy of formation of some thermally stable explosives in the gas and solid phases. These data were used for prediction of their detonation properties including heat of detonation, detonation pressure, detonation velocity, detonation temperature, electric spark sensitivity, impact sensitivity and deflagration temperature using appropriate methods. The range of different properties for these compounds are: crystal density 1.51–2.01 g cm⁻³, enthalpy of sublimation 346.4–424.7 kJ mol⁻¹, the solid phase enthalpy of formation 500.4–860.6 kJ mol⁻¹, heat of detonation 13.64–17.57 kJ g⁻¹, detonation pressure 33.0–37.0 GPa, detonation velocity 8.5–9.5 km s⁻¹, detonation temperature 5488–6234 K, electric spark sensitivity 7.89–9.47 J, impact sensitivity 21–38 J, deflagration temperature 560–586 K and power [%TNT] 207–276. The results show that two novel energetic compounds N,N′‐(diazene‐1,2‐diylbis(2,3,5,6‐tetranitro‐4,1‐phenylene))bis(5‐nitro‐4H‐1,2,4‐triazol‐3‐amine) (DDTNPNT3A) and 1,1′‐(diazene‐1,2‐diylbis(2,3,5,6‐tetranitro‐4,1‐phenylene))bis(3‐nitro‐1H‐1,2,4‐triazol‐5‐amine) (DDTNPNT5A) can be introduced as thermally explosives with high detonation performance.  相似文献   

    

Mohammad Hossein Keshavarz 《Propellants, Explosives, Pyrotechnics》2015,40(1):150-155

The prediction of phase change properties of energetic materials is important for the assessment of hazardous energetic materials. A novel user‐friendly computer code, written in Visual Basic, is introduced to predict the melting point and the enthalpy of fusion of energetic materials by only using their molecular structure parameters. It can be used for different types of energetic compounds including polynitro arenes, polynitro heteroarenes, acyclic and cyclic nitramines, nitrate esters, and nitroaliphatic. The predicted results were compared with several of the best available methods, which confirmed the higher reliability of the new computer code for some new and well‐known energetic compounds with complex molecular structures. This code can be used for designing of energetic compounds with desirable phase change properties.  相似文献   

    

Mohammad Hossein Tavassoli‐Kafrani  Jonathan M. Curtis  Frederik R. van de Voort 《European Journal of Lipid Science and Technology》2015,117(1):65-72

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Behzad Nazari  Hossein Nazockdast  Ali Asghar Katbab 《Polymer Engineering and Science》2014,54(8):1839-1847

The evolution of polyethylene/organoclay nanocomposite microstructure via shear and extentional flow fields was studied by tracing rheological behavior and nonisothermal crystallization kinetics. Although studying microstructure formed through flow fields, two phenomena were noticed: the breaking of three‐dimensional (3D) network containing filler–filler, filler–matrix, and matrix–matrix interactions, and organoclay platelets orientation. Utilizing nonlinear viscoelastic measurements and thermal analyses, it was proven that clay alignment was present only in large enough shear flows and all elongational flows. It was observed that regardless of the type of flow field and its magnitude, due to the breaking of 3D network, the extent of crystallization can be increased. The half‐lives of the crystallization of film samples and those samples subjected to large enough shear rates for clay platelets to be aligned decreased, proving the effect of clay orientation on crystallization rate increment. Based on endotherms observed through melting behavior studies of samples, it was proven that in elongation and large amplitude shear flows, clay orientation had resulted in forming thicker crystalline lamellae, likely because of forcing the adjacent polymer chains to align with the clay platelets. POLYM. ENG. SCI., 54:1839–1847, 2014. © 2013 Society of Plastics Engineers  相似文献   

    

Hossein Rahmani  S. Heydar Mahmoudi Najafi  Shohreh Saffarzadeh‐Matin  Alireza Ashori 《Polymer Engineering and Science》2014,54(11):2676-2682

Multi‐axial multi‐ply fabric (MMF) composites are becoming increasingly popular as reinforcing materials in high‐performance composites due to their high mechanical properties. This work aimed to study the effects of three variable parameters including fiber contents, numbers of plies, and layer orientations on the mechanical properties of MMF composites. Unidirectional carbon fibers and a two‐part epoxy resin were employed to produce the composite laminates using the manual lay‐up process. It was found that the mechanical properties of composites made with 5‐ply were slightly greater than 3‐ply composites. However, there was no highly significant difference between them. Generally, the angle‐ply of the composites showed the greatest effect on the mechanical properties compared with number of plies and layer orientations. The significant improvements in mechanical properties of the composites were further supported using scanning electron microscopy (SEM). Morphologies of the tensile fracture surfaces of composites revealed that the presence of fiber pulled out results in the creation of voids between the fibers and matrix polymer. This causes the mechanical properties of the composites to be reduced. Finally, the enhancement of mechanical properties of composites clearly confirmed that angle‐ply layer (0°,?35°,0°,+35°,0°) had the most significant reinforcing effect among other parameters evaluated. POLYM. ENG. SCI., 54:2676–2682, 2014. © 2013 Society of Plastics Engineers  相似文献   

    

Mohammad Hossein Sedaghat  Mohammad Hossein Ghazanfari  Mohsen Masihi 《加拿大化工杂志》2014,92(5):918-927

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Nader Mokhtarani  Ali Nasiri  Hossein Ganjidoust  S. Yashar Yasrobi 《臭氧:科学与工程》2014,36(6):540-548

The post-treatment of composting leachate via an ozonation process in laboratory scale was studied in batch mode. According to the experiments, the COD removal was 47% after 30 min of ozonation via 0.4 g/h ozone (equivalent to 2.8 mg O₃/mg COD removed) at pH 9. In this circumstance, the removal of color and turbidity was also 86% and 89%, respectively. Increasing the ozone mass flow rate higher than 0.4 g/h had no considerable effect on the process variables. However, increasing the reaction time had a significant effect on both the removal of color and on COD of the leachate. Experimental data indicated that complete removal of color and 51% removal of COD were achieved after about 40 min of ozonation via 0.4 g/h ozone (equivalent to 3.3 mg O₃/mg COD removed). The ozone consumption rate increased as the reaction progressed and reached 4.1 mg O₃/mg COD removed after 60 min.  相似文献   

    

Hossein Naeimi  Arash Heidarnezhad 《Journal of Sulfur Chemistry》2014,35(5):493-501

2-Arylbenzothiazoles were synthesized via condensation of 2-aminothiophenol and different aldehydes catalyzed by nano silica-supported boron trifluoride (nano BF₃/SiO₂) as an efficient and reusable catalyst in high yields and short reaction times. The reactions proceeded at room temperature under mild conditions to afford 2-arylbenzothiazole derivatives. The pure products were identified and characterized by physical and spectroscopic data such as IR, ¹H NMR, ¹³C NMR and Mass spectroscopy.  相似文献