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jih-2985
Radical Polymerization Kinetics of Hexyl Methacrylate in Dimethylsulfoxide Solution
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In this study, we conducted a series of polymerization studies of hexyl methacrylate in dimethyl sulfoxide with (0.1 - 0.4) mol dm-3 of monomer and (1 10-3 – 4 10-3) mol dm-3 of benzoyl peroxide as initiators at 70 °C. Using the well-known conversion vs. time technique, the effects of initiator and monomer concentration on the rate of polymerization (Rp) were studied. An initiator of order 0.35 was obtained in accordance with theory and a divergence from normal kinetics was detected with an order of 1.53 with respect to monomer concentration. The activation energy was determined to be (72.90) kJ mol-1, which does not correspond to the value of most thermally initiated monomers. The observed value of activation energy suggests that propagation and termination reactions have equal activation energy and the difference between them is nearly zero. The average degree of polymerization (DPn) decreased as benzoyl peroxide concentration increase whereas an increase in solvent polarity has slightly increased rate of polymerization value.

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Publication Date
Mon Sep 30 2002
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Kinetics of Hydrodesulfurization Catalyst Rejuvenation Process
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Publication Date
Tue Oct 02 2018
Journal Name
Iraqi Journal Of Physics
Study of in vitro and in vivo free radical scavenging activity for radioprotection of cerium oxide nanoparticles
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Nanoceria have shown numerous unique characteristics, such as biocompatibility and are excellent agents for biological applications. The aim of this study is to investigate cerium oxide nanoparticles for 2, 2- diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical scavenging activity and their ability to offer protection against ionizing radiation. In vitro antioxidant activity study of nanoceria particles has shown good free radical scavenging activity for DPPH radical assayed within a concentration range of 0.01 to 0.05 g/l, at higher concentrations of nanoparticles showed reverse trend in absorbance and inhibition indicating this finite rang of concentration is suitable for scavenging free radicals, also nanoparticles were found to ha

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Publication Date
Thu Nov 02 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Relation Between Oxygen Therapy Duration and Free Radical Generation In Infants With bronchiolitis
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Oxygen therapy (OT) is considered    an essential process for

survival for the i nfants with bronchiolitis > However, it may reach the status of being harmful when using it for along beriod . We , here, attempted to shed a light on relations between oxygen therapy duration(OTD)   and each of serum malondialdehyde (MDA) that is used as index for free radical generation , and serum albumin level , in infants with bronchiolitis . Our results   confirmed  that  (OTD) from (1-48) hr. was non effective,  while from 49 was very effective where a grave in crease in serum (MDA)level and a decrease in serum albumin concentration were observed during that time . The relation between age a

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Publication Date
Wed Dec 19 2018
Journal Name
Brazilian Journal Of Physics
The Induced Electron Density Effects of Swift Heavy Ions in Polymethyl Methacrylate
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Publication Date
Sun Sep 01 2013
Journal Name
Baghdad Science Journal
Antioxidant and free radical scavenging effects of Iraqi sumac ( Rhus coriaria L)
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This study was carried out to evaluate the antioxidant activity of Iraqi sumac seeds (Rhus coriaria. L) (Anacardiaceae). Total phenolic compounds and flavoniods were determined in three different sumac seed extracts (SSE) (aqueous,ethanolic and methanolic extract). For extraction Antioxidant activity of SSE were evaluated by various antioxidant assays, including total antioxidant capacity, reducing power,by using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, nitric oxide scavenging, Hydroxyl radical scavenging, and metal ion chelating activities. These various antioxidant activities were compared with ascorbic acid as a standard antioxidant.The results showed that the three(SSE), contained large amounts of phenolic and flavonio

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Publication Date
Fri Jun 01 2018
Journal Name
Materials Science-poland
Thermal and electrical properties of polyimide/PANI nanofiber composites prepared via in situ polymerization
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Abstract<p> Polyimide/polyaniline nanofiber composites were prepared by in situ polymerization with various weight percentages of polyaniline (PANI) nanofibers. X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR), proved the successful preparation of PANI nanofiber composite films. In addition, thermal stability of PI/PANI nanofiber composites was superior relative to PI, having 10 % gravimetric loss in the range of 623 °C to 671 °C and glass transition temperature of 289 °C to 297 °C. Furthermore, the values of the loss tangent tanδ and AC conductivity σAC of the nanocomposite films were notably higher than those of pure polyimide. The addition of 5 wt.% to 15 wt.% PANI</p> ... Show More
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Publication Date
Thu Jun 08 2023
Journal Name
Egyptian Journal Of Chemistry
Ring Opining polymerization of caprolactone And Antibacterial activity by Mixed Ligand of Metal(II) and (III)
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Reaction of L1 [((E)-N1-(nitrobenzylidene)benzene-1,2-diamine] and L2( m-aminophenol), and one equivalent of di- or tri-valent metals(Cr(ӀӀӀ), Mn(ӀӀ), Fe(ӀӀӀ), Co(ӀӀ), Ni(ӀӀ), Cu(ӀӀ) and Zn(ӀӀ) afforded the complexes [M(L1)(L2)2]Cl, M=Cr(ӀӀӀ) and Fe(ӀӀӀ) and the complexes [M(L1)(L2)2] M= Mn(ӀӀ), Co(ӀӀ), Ni(ӀӀ), Cu(ӀӀ) and Zn(ӀӀ). The structure of the Schiff base ligand and their complexes are characterized by (C:H:N), FT.IR, UV.Vis, 1HNMR, 13CNMR and mass spectral. The presence of metal in the complexes are characterized by flame atomic absorption. The spectral data of the complexes have revealed the octahedral geometry. The (L1), (L2) and mixed ligand metal complexes were screened for their ability as cataly

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Publication Date
Mon Apr 24 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Thermal Degradation Kinetics of Polyamide 6,6 Cable Ties by Thermogravimetric Analysis
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  The thermal degradation of cable ties of polyamide (PA6,6) neat and UV stabilized was investigated by thermogravimetry (TG) and its derivative (DTG) at several heating rates between 5 and 80 oC min-1  in helium atmosphere. High heating rates signal novel peaks in the DTG curves that indicate melting temperature of PA6,6. The kinetic parameters calculated via isoconversion and nonisothermal data using the Flynn-Wall-Ozawa, Kissinger and CoatsRedfern methods showed comparable activation energy values. Exposure of the ties to outdoor environment causes pre-mature stress cracking and brittle failure due to prevalence of crosslinking reaction occurring in the polymer chains

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Publication Date
Sat Mar 31 2018
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Kinetics of Thermal Pyrolysis of High-Density Polyethylene
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Thermal pyrolysis kinetics of virgin high-density polyethylene (HDPE) was investigated. Thermal pyrolysis of HDPE was performed using a thermogravimetric analyzer in nitrogen atmosphere under non-isothermal conditions at different heating rates 4, 7, 10 °C/min. First-order decomposition reaction was assumed, and for the kinetic analysis Kissinger-Akahira-Sunose(KAS), Flynn-Wall-Ozawa(FWO) and Coats and Redfern(CR) method were used. The obtained values of  average activation energy by the KAS and FWO methods were equal to137.43 and 141.52 kJ/mol respectively, these values were considered in good agreement, where the  average activation energy value obtained by CR equation methods was slightly different which equal to 153.16 kJ/

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Publication Date
Tue Feb 18 2020
Journal Name
Egyptian Journal Of Chemistry
Corrosion Protection of Pure Titanium Implant in Artificial Saliva by Electro-Polymerization of Poly Eugenol
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IN this work, a titanium dental implant was modified by electro-polymerized of 4-allyl-2-methoxyphenol (Eugenol) using direct current lower than 3.5 volt. The modification of titanium dental implant was achieved to improve its corrosion resistant. Fourier transform infrared spectroscopy (FTIR) was employed to confirm the electro-polymerization of Eugenol to Poly Eugenol (PE) on pure titanium. Deposition of PE on titanium was confirmed by X-ray diffraction and was characterized by thermogravimetric analysis (TGA). The surface morphology of polymeric film were examined through scanning electron microscopy (SEM). Coated titanium by (PE) revealed a good corrosion protection efficiency even at temperature ranged (293-323)K in artificial saliva.

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