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A new closure-approximated model based on the Cohen/Pad? (CP) spring law is presented. Because it is inspired by the finitely extensible non-linear elastic Peterlin version (FENE-P), the model is titled CP-P. The rheological behaviors in simple and pressure-driven pipe shear flows in both the steady-state and time-dependent conditions are compared between the two models. To this end, a new approach based on the second moment Fokker–Planck equation instead of the Langevin equation is developed, which was confirmed by means of the existing analytical and stochastic data prior to its use. Application of this new approach is restricted to the closure approximated models but at a much less computational expense than the CONNFFES
Polypropylene was blended with polybutadiene in an internal mixer in order to improve its toughness. The rubber content ranged from 10 to 20 wt.% and dicumyl peroxide (DCP) was added to provide required radicals for dynamic crosslinking of polybutadiene, and for in-situ compatibilization of the phases. This was done using two sequences of mixing. In addition, zinc dimethacrylate was utilized as a co-agent to control chain scission of PP, enhance the interfacial reactions and increase compatibility of the components. In obtaining the optimum blend, the Taguchi orthogonal experimental design was applied and results of Izod impact strength test were concordantly related to crystallinity of the polypropylene, morphology of the blends and reacti
The temporal rheological behavior of FENE and FENE-P models is investigated using the flow in a circular, straight tube. The CONNFFESSIT approach is applied to simulate transient Hagen–Poiseuille flow for different pressure drops and model parameters. The material functions for steady and unsteady flow were extracted and compared with the reported values in the literature when it was available. For the case of the FENE model, where there is no analytical solution, the relationship between model parameters and rheological behavior has been discussed and compared with the FENE-P model.
The morphology, rheology, and mechanical properties of the dynamically vulcanized thermoplastic elastomer based on EPDM/PP (60/40, w:w) containing 5, 10, and 20% of cellulose short fiber were studied. From the results it was found that addition of 5% of cellulose fiber has no significant effect on the maximum torque associated with the dynamic vulcanization stage, while higher concentration of fibers decreased the maximum torque. These results were explained in terms of influence of cellulose fibers on the extent of agglomeration formed between the cured rubber particles. The results of tensile test performed on the samples showed that incorporation of 5% of cellulose fibers into the sample has an increasing effect on elongation at break
A new closure-approximated model based on the Cohen/Pad? (CP) spring law is presented. Because it is inspired by the finitely extensible non-linear elastic Peterlin version (FENE-P), the model is titled CP-P. The rheological behaviors in simple and pressure-driven pipe shear flows in both the steady-state and time-dependent conditions are compared between the two models. To this end, a new approach based on the second moment Fokker–Planck equation instead of the Langevin equation is developed, which was confirmed by means of the existing analytical and stochastic data prior to its use. Application of this new approach is restricted to the closure approximated models but at a much less computational expense than the CONNFFESSIT-like simula
Biodegradable cellulose acetate (CA) membranes were prepared via phase inversion induced by immersion precipitation method. Acetic acid and deionized water were used as a solvent and a non‐solvent, respectively. The modifying effect of gelatin and zinc oxide (ZnO) nanoparticles additives was investigated on the membranes in terms of water flux, protein rejection percentage, and fouling ability during 2 hours of bovine serum albumin separation from aqueous solution. Additionally, specimens were characterized using scanning electron microscopy (SEM), Fourier‐transform infrared spectroscopy (FTIR), tensile test, contact angle technique, and porosity measurement. The incorporation of gelatin and ZnO nanoparticles into the cellulose acetate