scholarly journals Effect of impurities in the crude glycerol polymerization reaction to produce polyglycerol

2019 ◽  
Vol 9 (2) ◽  
pp. 89-98
Author(s):  
Gustavo E. Ramirez Caballero ◽  
Carolina Ardila Suárez ◽  
Jeimmy Zulay Rojas Cristancho ◽  
Jennifer Paola Pineda Martínez ◽  
Alvaro Ramírez García
Keyword(s):  
Experimental Design ◽  
Crude Glycerol ◽  
Low Cost ◽  
Value Added ◽  
Polymerization Reaction ◽  
Reaction Products ◽  
Reaction Conditions ◽  
Raw Glycerol ◽  
Molecular Weights ◽  
Effect Of Impurities

Crude glycerol is a low-cost biodiesel industry co-product in a ratio of 1:10 with the main product. The large quantities of crude glycerol produced affect the biodiesel and glycerol markets. Consequently, the exploration of new applications for crude glycerol becomes crucial. As the composition of crude glycerol differs significantly from that of purified glycerol, this work was focused on studying the effect of crude glycerol impurities on its polymerization, as this process, at the same reaction conditions established for the polymerization of purified glycerol, did not result in polymeric products. To identify the reason for this result, the crude glycerol was fully characterized to identify its composition. Hence, an experimental design using simulated crude glycerol was performed to study the effect of the most abundant impurities in the raw glycerol on the polymerization andthe impurities that would persist with such reaction conditions, such as soap and sodium. The response variable for the experimental design was the hydroxyl number of the reaction products. FT-IR spectroscopy was used to analyze differences among the reaction products obtained from different treatments. The presence of soap was identified as primary inhibitory factor and the bottleneck in the formation of polyglycerol via polymerization of crude glycerol. Molecular weights of the polymerization reaction products were determined and analyzed as per the MALDI-TOF technique. The identification of the effect of impurities of crude glycerol polymerization suggests new routes for using it in the production of high value-added chemicals.

scholarly journals Calcium Hydroxyapatite: A Highly Stable and Selective Solid Catalyst for Glycerol Polymerization

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1247
Author(s):  
Negisa Ebadipour ◽  
Sébastien Paul ◽  
Benjamin Katryniok ◽  
Franck Dumeignil
Keyword(s):  
Catalytic Activity ◽  
Calcium Hydroxyapatite ◽  
Polymerization Reaction ◽  
Solid Catalyst ◽  
High Catalytic Activity ◽  
Reaction Products ◽  
Icp Oes ◽  
Reaction Conditions ◽  
Glycerol Conversion ◽  
The Stability

Calcium-based catalysts are of high interest for glycerol polymerization due to their high catalytic activity and large availability. However, their poor stability under reaction conditions is an issue. In the present study, we investigated the stability and catalytic activity of Ca-hydroxyapatites (HAps) as one of the most abundant Ca-source in nature. A stochiometric, Ca-deficient and Ca-rich HAps were synthesized and tested as catalysts in the glycerol polymerization reaction. Deficient and stochiometric HAps exhibited a remarkable 100% selectivity to triglycerol at 15% of glycerol conversion at 245 °C after 8 h of reaction in the presence of 0.5 mol.% of catalyst. Moreover, under the same reaction conditions, Ca-rich HAp showed a high selectivity (88%) to di- and triglycerol at a glycerol conversion of 27%. Most importantly, these catalysts were unexpectedly stable towards leaching under the reaction conditions based on the ICP-OES results. However, based on the catalytic tests and characterization analysis performed by XRD, XPS, IR, TGA-DSC and ICP-OES, we found that HAps can be deactivated by the presence of the reaction products themselves, i.e., water and polymers.

scholarly journals Calcium Hydroxyapatite: A Highly Stable and Selective Solid Catalyst for Glycerol Polymerization

2021 ◽  
Author(s):  
Negisa Ebadipour ◽  
Sébastien Paul ◽  
Benjamin Katryniok ◽  
Franck Dumeignil
Keyword(s):  
Catalytic Activity ◽  
Calcium Hydroxyapatite ◽  
Polymerization Reaction ◽  
Solid Catalyst ◽  
High Catalytic Activity ◽  
Reaction Products ◽  
Icp Oes ◽  
Reaction Conditions ◽  
Glycerol Conversion ◽  
The Stability

Abstract: Calcium-based catalysts are of a high interest for glycerol polymerization due to their high catalytic activity and large availability. However, their poor stability under reaction conditions is an issue. In the present study, we investigated the stability and catalytic activity of Ca-hydroxyapatites (HAps) as one of the most abundant Ca-source in nature. A stochiometric, a Ca-deficient and a Ca-rich HAps have been synthetized and tested as catalysts in the glycerol polymerization reaction. Deficient and stochiometric HAps exhibited a remarkable 100% selectivity to triglycerol at 15 % of glycerol conversion at 245 °C after 8 h of reaction in the presence 0.5 mol.% of catalyst. Moreover, under the same reaction conditions, Ca-rich HAp showed a high selectivity (88 %) to di- and triglycerol at a glycerol conversion of 27 %. Most importantly, these catalysts were unexpectedly stable towards leaching under the reaction conditions based on the ICP-OES results. However, based on the catalytic tests and characterization analysis performed by XRD, XPS, IR, TGA-DSC and ICP-OES, we found that HAps can be deactivated by the presence of the reaction products themselves, i.e., water and polymers.

Novel CO2-Thermic Oxidation Process with Mg-Based Intermetallic Compounds and Its Application to Energy Storage Materials

2018 ◽  
Author(s):  
Younghwan Cha ◽  
Jung-In Lee ◽  
Panpan Dong ◽  
Xiahui Zhang ◽  
Min-Kyu Song
Keyword(s):  
Intermetallic Compounds ◽  
Oxidation Process ◽  
Value Added ◽  
Energy Storage Materials ◽  
Reaction Products ◽  
Materials Synthesis ◽  
Energy Materials ◽  
A Value ◽  
Carbon Coated ◽  
Novel Strategy

A novel strategy for the oxidation of Mg-based intermetallic compounds using CO<sub>2</sub> as an oxidizing agent was realized via simple thermal treatment, called ‘CO2-thermic Oxidation Process (CO-OP)’. Furthermore, as a value-added application, electrochemical properties of one of the reaction products (carbon-coated macroporous silicon) was evaluated. Considering the facile tunability of the chemical/physical properties of Mg-based intermetallics, we believe that this route can provide a simple and versatile platform for functional energy materials synthesis as well as CO<sub>2</sub> chemical utilization in an environment-friendly and sustainable way.

scholarly journals Chitosan Adsorbent Derivatives for Pharmaceuticals Removal from Effluents: A Review

Macromol ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 130-154
Author(s):  
Efstathios V. Liakos ◽  
Maria Lazaridou ◽  
Georgia Michailidou ◽  
Ioanna Koumentakou ◽  
Dimitra A. Lambropoulou ◽  
...  
Keyword(s):  
Emerging Contaminants ◽  
Low Cost ◽  
Value Added ◽  
Ph Effects ◽  
Hydroxyl Groups ◽  
Research Papers ◽  
Natural Polysaccharide ◽  
Best Fitting ◽  
Isotherm And Kinetic Models ◽  
Published Research

Chitin is mentioned as the second most abundant and important natural biopolymer in worldwide scale. The main sources for the extraction and exploitation of this natural polysaccharide polymer are crabs and shrimps. Chitosan (poly-β-(1 → 4)-2-amino-2-deoxy-d-glucose) is the most important derivative of chitin and can be used in a wide variety of applications including cosmetics, pharmaceutical and biomedical applications, food, etc., giving this substance high value-added applications. Moreover, chitosan has applications in adsorption because it contains amino and hydroxyl groups in its molecules, and can thus contribute to many possible adsorption interactions between chitosan and pollutants (pharmaceuticals/drugs, metals, phenols, pesticides, etc.). However, it must be noted that one of the most important techniques of decontamination is considered to be adsorption because it is simple, low-cost, and fast. This review emphasizes on recently published research papers (2013–2021) and briefly describes the chemical modifications of chitosan (grafting, cross-linking, etc.), for the adsorption of a variety of emerging contaminants from aqueous solutions, and characterization results. Finally, tables are depicted from selected chitosan synthetic routes and the pH effects are discussed, along with the best-fitting isotherm and kinetic models.

An insight into an electro-catalytic reactor concept for high value-added production from crude glycerol: Optimization, electrode passivation, product distribution, and reaction pathway identification

2021 ◽  
Vol 172 ◽  
pp. 130-144
Author(s):  
Ali Khosravanipour Mostafazadeh ◽  
Maria Samantha De La Torre ◽  
Yessika Padilla ◽  
Patrick Drogui ◽  
Satinder Kaur Brar ◽  
...  
Keyword(s):  
Crude Glycerol ◽  
Reaction Pathway ◽  
Value Added ◽  
Product Distribution ◽  
Catalytic Reactor ◽  
Electrode Passivation ◽  
Insight Into

scholarly journals Synthesis of poly (n-butyl acrylate) with tempo by nitroxide mediated polymerization method

2021 ◽  
pp. 096739112110245
Author(s):  
Amrita Sharma ◽  
PP Pande
Keyword(s):  
Butyl Acrylate ◽  
Low Cost ◽  
Polymerization Process ◽  
Polymerization Reaction ◽  
High Concentration ◽  
Acrylate Monomer ◽  
Controlled Polymerization ◽  
Acrylate Monomers ◽  
Nitroxide Mediated Polymerization ◽  
Polymerization Method

It has been observed that acrylate monomers are very difficult to polymerize with the low cost nitroxide catalyst 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO). Therefore, costly acyclic nitroxides such as N-tert-butyl-N-(1-diethylphosphono-2,2-dimethyl)-N-oxyl, (SG1), 2,2,5-Trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) and TIPNO derivatives have to be used for the polymerization of the acrylic acid derivatives. There are very few reports on the use of TEMPO-derivatives toward the polymerization of n-butyl acrylate. Generally different reducing agents viz. glucose, ascorbic acid, hydroxyacetone etc. have been used to destroy excess TEMPO during the polymerization reaction. The acrylate polymerizations fail in the presence of TEMPO due to the strong C–O bond formed between the acrylate chain end and nitroxide. To the best of our knowledge, no literature report is available on the use of TEMPO without reducing agent or high temperature initiators, toward the polymerization of n-butyl acrylate. The present study has been carried out with a view to re-examine the application of low cost nitroxide TEMPO, so that it can be utilized towards the polymerization of acrylate monomers (e.g. n-butyl acrylate). We have been able to polymerize n-butyl acrylate using the nitroxide TEMPO as initiator (via a macroinitiator). In this synthesis, a polystyrene macroinitiator was synthesized in the first step from TEMPO, after this TEMPO end-capped styrene macroinitiator (PSt-TEMPO) is used to polymerize n-butyl acrylate monomer. The amount of macroinitiator taken was varied from 0.05% to 50% by weight of n-butyl acrylate monomer. The polymerization was carried out at 120°C by bulk polymerization method. The experimental findings showed a gradual increase in molecular weight of the polymer formed and decrease in the polydispersity index (PDI) with increase in amount of PSt-TEMPO macroinitiator taken. In all experiments conversion was more than 80%. These results indicate that the polymerization takes place through controlled polymerization process. Effect of different solvents on polymerization has also been investigated. In the following experiments TEMPO capped styrene has been used as macroinitiator leading to the successful synthesis of poly n-Butyl acrylate. It has been found that styrene macroinitiator is highly efficient for the nitroxide mediated polymerization, even in very small concentration for the synthesis of poly n-butyl acrylate. High concentration of macroinitiator results in the formation of block copolymers of polystyrene and poly ( n-butyl acrylate) viz. polystyrene-block-poly-( n-butyl acrylate). The use of TEMPO toward controlled polymerization is of much importance, because it is the nitroxide commercially available at the lowest cost.

scholarly journals Optimizing the Reaction Conditions for the Formation of Fumarate via Trans-Hydrogenation

2021 ◽  
Author(s):  
Laura Wienands ◽  
Franziska Theiß ◽  
James Eills ◽  
Lorenz Rösler ◽  
Stephan Knecht ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Thermal Equilibrium ◽  
Reaction Rate ◽  
Low Cost ◽  
Hydrogen Gas ◽  
Metabolic Imaging ◽  
Reaction Conditions ◽  
Precursor Molecule ◽  
Solution Preparation

AbstractParahydrogen-induced polarization is a hyperpolarization method for enhancing nuclear magnetic resonance signals by chemical reactions/interactions involving the para spin isomer of hydrogen gas. This method has allowed for biomolecules to be hyperpolarized to such a level that they can be used for real time in vivo metabolic imaging. One particularly promising example is fumarate, which can be rapidly and efficiently hyperpolarized at low cost by hydrogenating an acetylene dicarboxylate precursor molecule using parahydrogen. The reaction is relatively slow compared to the timescale on which the hyperpolarization relaxes back to thermal equilibrium, and an undesirable 2nd hydrogenation step can convert the fumarate into succinate. To date, the hydrogenation chemistry has not been thoroughly investigated, so previous work has been inconsistent in the chosen reaction conditions in the search for ever-higher reaction rate and yield. In this work we investigate the solution preparation protocols and the reaction conditions on the rate and yield of fumarate formation. We report conditions to reproducibly yield over 100 mM fumarate on a short timescale, and discuss aspects of the protocol that hinder the formation of fumarate or lead to irreproducible results. We also provide experimental procedures and recommendations for performing reproducible kinetics experiments in which hydrogen gas is repeatedly bubbled into an aqueous solution, overcoming challenges related to the viscosity and surface tension of the water.

scholarly journals Redox initiation in semicontinuous polymerization to search for specific mechanical properties of copolymers

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 613-623
Author(s):  
José Manuel Sandoval-Díaz ◽  
Francisco Javier Rivera-Gálvez ◽  
Marta Fernández-García ◽  
Carlos Federico Jasso-Gastinel
Keyword(s):  
Low Cost ◽  
Mechanical Analysis ◽  
Industrial Applications ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Polymerization Reaction ◽  
Redox Initiation ◽  
Initiation System ◽  
Feeding Profile ◽  
Chain Composition

AbstractIn this work, for a semicontinuous emulsion polymerization reaction, it is shown that using a redox initiation system at 40°C, substantial modifications in copolymer chain composition with conversion can be easily obtained. To test controllable trajectories for comonomer feeding, linear and parabolic profiles were chosen to get different types of chain composition variations for the 50/50 w/w styrene/n-butyl acrylate system. For the “forced composition copolymers,” the molecular weight averages and distribution were obtained by size exclusion chromatography. The composition along conversion was followed by proton nuclear magnetic resonance to determine the weight composition distribution (WCD) of the copolymer chains. Mechanodynamic (dynamic-mechanical analysis), tensile, and hardness tests exhibited consistent results depending on the WCD that outcomes from the respective feeding profile. The results confirm that this methodology is of great potential for industrial applications when looking for synergy in copolymer properties, and low-cost processes.

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