Keywords elastomer, treatment, oxidation, mediated electrochemical oxidation, silver (II) Polymer... more Keywords elastomer, treatment, oxidation, mediated electrochemical oxidation, silver (II) Polymerization Quarterly, 2017 Volume 7, Number 1 Pages 94-101 D ue to their high redox potential, metal ion couples such as silver (I)/silver (II), cerium (III)/ cerium (IV), cobalt (III)/cobalt (II) and manganese (III)/ manganese (II) are used as strong and stable oxidants in mediated electrochemical oxidation (MEO) method for surface modification of polymers, specially elastomers. Silver which has the highest redox potential and oxidation effects of metals is more used in mediated electrochemical oxidation methods. Because of the importance of surface modification and oxidation of elastomers in secondary applications such as improvement of adhesion or compatibility and also for both economic and environmental reasons, mediated electrochemical oxidation technique has received increasing attention. Enhancement of surface oxygen content, variations in surface morphology, topography, hydrophilic...
In this work, the role of comonomer content of 1-hexene-medium density polyethylene (MDPE) copoly... more In this work, the role of comonomer content of 1-hexene-medium density polyethylene (MDPE) copolymer, synthesized using Phillips catalyst, on thermal behavior parameters such as: crystallization, melting temperature and thermal degradation was investigated in detail. The copolymer was fractionated to homogenous short-chain branching (SCB) fractions by "preparative temperature rising elution fractionation" (P-TREF) method and then it was subjected to thermal analyses. A broad chemical composition distribution (CCD) in terms of SCB content and molecular weight (Mw) was observed by P-TREF and gel permeation chromatography (GPC), respectively. Based on P-TREF results, a parabolic relationship between methylene sequence length (MSL) and elution temperature (ET) was presented. Differential scanning calorimetry (DSC) showed distinct, well-defined melting peaks over a 22 °C temperature range for SCB contents of about 3-12 (br/1000 C). The variations in physical characteristics suc...
In this research, deep eutectic solvents (DESs) were prepared and employed as electrolyte in Nafi... more In this research, deep eutectic solvents (DESs) were prepared and employed as electrolyte in Nafion membranes for PEM fuel cell application.
The electro-generation kinetic of Ag (II) in nitric acid media was initially investigated experim... more The electro-generation kinetic of Ag (II) in nitric acid media was initially investigated experimentally, assessed with a theoretical model which showed a good agreement. The reaction was found to be kinetic-controlled on the DSA-O2 anode surface. The Arrhenius model was employed and activation energy was estimated to be 44±2 kJ.mol-1. Optimization studies at constant potential showed Ag (I) and HNO3 concentrations promote the generation rate of Ag (II) while temperature and anolyte flow rate have inverse effects. The optimum conditions were found to be: Anolyte: T≤ 29 ◦C, Flow rate: 100 ml/min, 0.5M initial Ag(I) in 6M nitric acid as supporting electrolyte, Catholyte: 8M nitric acid. The degradation kinetic of polystyrene (PS) by silver (II) process was then demonstrated and found to be fast and first order respect to Ag(II). Model validation was carried out successfully. FTIR results confirmed the degradation of PS.
Keywords elastomer, treatment, oxidation, mediated electrochemical oxidation, silver (II) Polymer... more Keywords elastomer, treatment, oxidation, mediated electrochemical oxidation, silver (II) Polymerization Quarterly, 2017 Volume 7, Number 1 Pages 94-101 D ue to their high redox potential, metal ion couples such as silver (I)/silver (II), cerium (III)/ cerium (IV), cobalt (III)/cobalt (II) and manganese (III)/ manganese (II) are used as strong and stable oxidants in mediated electrochemical oxidation (MEO) method for surface modification of polymers, specially elastomers. Silver which has the highest redox potential and oxidation effects of metals is more used in mediated electrochemical oxidation methods. Because of the importance of surface modification and oxidation of elastomers in secondary applications such as improvement of adhesion or compatibility and also for both economic and environmental reasons, mediated electrochemical oxidation technique has received increasing attention. Enhancement of surface oxygen content, variations in surface morphology, topography, hydrophilic...
In this work, the role of comonomer content of 1-hexene-medium density polyethylene (MDPE) copoly... more In this work, the role of comonomer content of 1-hexene-medium density polyethylene (MDPE) copolymer, synthesized using Phillips catalyst, on thermal behavior parameters such as: crystallization, melting temperature and thermal degradation was investigated in detail. The copolymer was fractionated to homogenous short-chain branching (SCB) fractions by "preparative temperature rising elution fractionation" (P-TREF) method and then it was subjected to thermal analyses. A broad chemical composition distribution (CCD) in terms of SCB content and molecular weight (Mw) was observed by P-TREF and gel permeation chromatography (GPC), respectively. Based on P-TREF results, a parabolic relationship between methylene sequence length (MSL) and elution temperature (ET) was presented. Differential scanning calorimetry (DSC) showed distinct, well-defined melting peaks over a 22 °C temperature range for SCB contents of about 3-12 (br/1000 C). The variations in physical characteristics suc...
In this research, deep eutectic solvents (DESs) were prepared and employed as electrolyte in Nafi... more In this research, deep eutectic solvents (DESs) were prepared and employed as electrolyte in Nafion membranes for PEM fuel cell application.
The electro-generation kinetic of Ag (II) in nitric acid media was initially investigated experim... more The electro-generation kinetic of Ag (II) in nitric acid media was initially investigated experimentally, assessed with a theoretical model which showed a good agreement. The reaction was found to be kinetic-controlled on the DSA-O2 anode surface. The Arrhenius model was employed and activation energy was estimated to be 44±2 kJ.mol-1. Optimization studies at constant potential showed Ag (I) and HNO3 concentrations promote the generation rate of Ag (II) while temperature and anolyte flow rate have inverse effects. The optimum conditions were found to be: Anolyte: T≤ 29 ◦C, Flow rate: 100 ml/min, 0.5M initial Ag(I) in 6M nitric acid as supporting electrolyte, Catholyte: 8M nitric acid. The degradation kinetic of polystyrene (PS) by silver (II) process was then demonstrated and found to be fast and first order respect to Ag(II). Model validation was carried out successfully. FTIR results confirmed the degradation of PS.
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