- Efficient Plastic Waste Recycling to Value-Added Products by Integrated Biomass Processing
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The industrial production of polymeric materials is continuously increasing, but sustainable concepts directing towards a circular economy remain rather elusive. The present investigation focuses on the recycling of polyoxymethylene polymers, facilitated through combined catalytic processing of polymer waste and biomass-derived diols. The integrated concept enables the production of value-added cyclic acetals, which can flexibly function as solvents, fuel additives, pharmaceutical intermediates, and even monomeric materials for polymerization reactions. Based on this approach, an open-loop recycling of these waste materials can be envisaged in which the carbon content of the polymer waste is efficiently utilized as a C1 building block, paving the way to unprecedented possibilities within a circular economy of polyoxymethylene polymers.
- Beydoun, Kassem,Klankermayer, Jürgen
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Read Online
- Reactions of cyclic boric acids esters with paraformaldehyde
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Reactions of five- and six-membered cyclic esters of boric acids with paraformaldehyde lead to the corresponding 1,3-dioxacycloalkanes. It is shown that trans-isomers of 2,4,5-substituted 1,3,2-dioxaborinanes react faster than their cis-isomers.
- Brusilovskii, Yu. E.,Kuznetsov
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Read Online
- A study on the cataluminescence of propylene oxide on FeNi layered double hydroxides/graphene oxide
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In this work, FeNi layered double hydroxides/graphene oxide (FeNi LDH/GO) was prepared, which exhibits excellent selective cataluminescent performance towards propylene oxide. The selectivity and sensitivity of the cataluminescence (CTL) reaction were investigated in detail. Moreover, the catalytic reaction mechanism, including the intermediate products and the conversion of reactants to products, was discussed based on both the experimental and computational results. Furthermore, the proposed FeNi LDH/GO based CTL sensor was successfully applied for the determination of propylene oxide residue in fumigated raisins, which indicates extensive application potential for rapid food safety evaluation.
- Li, Ming,Hu, Yufei,Li, Gongke
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p. 11823 - 11830
(2021/07/11)
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- Biomass alcoholysis method for petroleum-based plastic POM
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The invention discloses a biomass alcoholysis method for petroleum-based plastic POM. According to the method, simple biomass derivative alcohol and the petroleum-based plastic POM are allowed to generate a cyclic acetal product through dehydration condensation under catalytic conditions; low reaction cost and high added value are realized, and only water is byproduced and is easy to separate; and an obtained product has high added value, can be used for preparing organic solvents such as lignin and chromatographic analysis solvents, metal surface treatment agents or medical intermediates and monomers, realizes green, efficient and low-cost recovery, and has a high practical application value.
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Paragraph 0030-0051
(2021/05/01)
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- 4-methyl-1,3-dioxolane preparation method
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The invention discloses a 4-methyl-1,3-dioxolane preparation method, which comprises: 1, adding a solvent, formaldehyde and a catalyst into a reactor, and heating to 60 DEG C, wherein the solvent is an organic solvent, has a boiling point of more than 120 DEG C and is immiscible with water, and the catalyst is a solid base catalyst; 2, adding 1, 2-propylene glycol into the reactor in a dropwise manner, and controlling the reaction temperature at 65-95 DEG C; 3, after the reaction is finished, separating the liquid to obtain a water layer and a crude product layer, and dewatering and filteringthe crude product layer to obtain a crude product; and 4, adding a polymerization inhibitor into the crude product, and carrying out reduced pressure rectification purification to obtain a pure product, ie., the 4-methyl-1, 3-dioxolane. According to the invention, the method has the following advantages that the purification difficulty is low, the byproducts are few, and the yield is high; the environmental affinity is good, and the national sustainable development policy is met; the waste is little, the treatment is easy, the process route is simple, the reaction is easy to control, and the method is suitable for industrial production; and the product purity is high and can reach more than 99.5%, and the water content is low.
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Paragraph 0024-0027
(2020/03/13)
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- A study of the oxidehydration of 1,2-propanediol to propanoic acid with bifunctional catalysts
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The gas-phase oxidehydration (ODH) of 1,2-propanediol to propionic acid has been studied as an intermediate step in the multi-step transformation of bio-sourced glycerol into methylmethacrylate. The reaction involves the dehydration of 1,2-propanediol into propionaldehyde, which occurs in the presence of acid active sites, and a second step of oxidation of the aldehyde to the carboxylic acid. The two reactions were carried out using a cascade strategy and multifunctional catalysts, made of W-Nb-O, W-V-O and W-Mo-V-O hexagonal tungsten bronzes, the same systems which are also active and selective in the ODH of glycerol into acrylic acid. Despite the similarities of reactions involved, the ODH of 1,2-propanediol turned out to be less selective than glycerol ODH, with best yield to propanoic acid no higher than 13percent, mainly because of the parallel reaction of oxidative cleavage, occurring on the reactant itself, which led to the formation of C1-C2 compounds.
- Bandinelli, Claudia,Basile, Francesco,Cavani, Fabrizio,Concepcion, Patricia,De Maron, Jacopo,Dimitratos, Nikolaos,Lambiase, Barbara,Nieto, Jose Manuel Lopez,Tabanelli, Tommaso
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- Ruthenium-Catalyzed Synthesis of Cyclic and Linear Acetals by the Combined Utilization of CO2, H2, and Biomass Derived Diols
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Herein a transition-metal catalyst system for the selective synthesis of cyclic and linear acetals from the combined utilization of carbon dioxide, molecular hydrogen, and biomass derived diols is presented. Detailed investigations on the substrate scope enabled the selectivity of the reaction to be largely guided and demonstrated the possibility of integrating a broad variety of substrate molecules. This approach allowed a change between the favored formation of cyclic acetals and linear acetals, originating from the bridging of two diols with a carbon-dioxide based methylene unit. This new synthesis option paves the way to novel fuels, solvents, or polymer building blocks, by the recently established “bio-hybrid” approach of integrating renewable energy, carbon dioxide, and biomass in a direct catalytic transformation.
- Beydoun, Kassem,Klankermayer, Jürgen
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supporting information
p. 11412 - 11415
(2019/07/18)
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- State-of-the-art catechol porphyrin COF catalyst for chemical fixation of carbon dioxide: Via cyclic carbonates and oxazolidinones
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A highly porous, crystalline catechol porphyrin COF was synthesized and applied as an organocatalyst for the chemical fixation of carbon dioxide to synthesize value-added chemicals such as cyclic carbonates and oxazolidinones under solvent-free and transition-metal-free conditions. The high surface area and the functionalities of the COF catalyst act synergistically to activate the starting material. The 2,3-DhaTph shows excellent activity towards cyclic carbonates at the atmospheric pressure of carbon dioxide. Additionally, this catalytic system is recyclable in nature and provides a higher turnover number than previously reported organocatalysts.
- Saptal, Vitthal,Shinde, Digambar Balaji,Banerjee, Rahul,Bhanage, Bhalchandra M.
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p. 6152 - 6158
(2016/08/05)
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- Selective lewis acid catalyzed assembly of phosphonomethyl ethers: Three-step synthesis of tenofovir
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Described herein is a novel Lewis acid catalyzed rearrangement-coupling of oxygen heterocycles and bis(diethylamino)chlorophosphine that provides direct formation of the phosphonomethyl ether functionality found in several important antiretroviral agents. A wide range of dioxolanes and 1,3-dioxanes may be employed, furnishing the desired products in good yield. The utility of this method is demonstrated in a novel synthesis of tenofovir, an antiretroviral drug used in the treatment of HIV/AIDS and hepatitis B.
- Ocampo, Charles E.,Lee, Doris,Jamison, Timothy F.
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supporting information
p. 820 - 823
(2015/03/18)
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- Formation of cyclic acetals in interaction of formaldehyde with 1,2-propylene glycol and diethylene glycol
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Formation and hydrolysis of 4-methyl-1,3-dioxolane and 1,3,6-trioxocane in aqueous-glycol solutions of formaldehyde in the presence of sulfuric acid as a catalyst were studied. The dependences of rate constants on temperature (in the temperature range 40-80°C), the concentration of the catalyst (0-0.5 mol/l), and the content of water (0.5-15 mol/l) were obtained. The introduction of the methyl substituent into position 4 of 1,3-dioxolane somewhat decreased the rate constants for the formation and hydrolysis reactions. A similar effect was observed for the eight-membered ring of 1,3,6-trioxocane in comparison with 1,3-dioxolane with a five-membered ring.
- Balashov,Danov,Chernov
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p. 917 - 920
(2007/10/03)
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- Identification of 1,3-dioxanes and 1,3-dioxolanes as malodorous compounds at trace levels in river water, groundwater, and tap water
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A study of organic compounds imparting odor problems in river waters and groundwaters has been conducted. The Tordera aquifer located in Barcelona and Girona (NE Spain) is the water supply reserve for many seasonally crowded villages on the coast. Closed loop stripping analysis (CLSA) and flavor profile analysis (FPA) have been employed as analytical tools to identify the compounds responsible for the odor complaints. The feasibility of purge-and- trap (P and T) has also been evaluated. The 2-alkyl-5,5-dimethyl-1,3-dioxanes and 2-alkyl-4-methyl-1,3-dioxolanes were the most significant compounds identified in river water and groundwater with a threshold odor of 10 ng/L for 2-ethyl-5,5-dimethyl-1,3-dioxane (2EDD), the most malodorous compound. The analyses were carried out by HRGC/MS, and the synthesized 1,3-dioxanes and dioxolanes were characterized by CI-MS and EI-MS/MS techniques. A company, currently manufacturing saturated and unsaturated polyester resins, located in the upper course of the river, produced these compounds as byproducts during the synthesis of resins. The pollution by dioxanes and dioxolanes affected all the aquifer and slowly diminished to the ppt levels when the company was forced to correctly treat their wastewaters. Additional examples of the presence of dioxanes and dioxolanes in wastewaters of other resin plants and also tap water of Barcelona are shown. A study of organic compounds imparting odor problems in river waters and groundwaters has been conducted. The Tordera aquifer located in Barcelona and Girona (NE Spain) is the water supply reserve for many seasonally crowded villages on the coast. Closed loop stripping analysis (CLSA) and flavor profile analysis (FPA) have been employed as analytical tools to identify the compounds responsible for the odor complaints. The feasibility of purge-and-trap (P&T) has also been evaluated. The 2-alkyl-5,5-dimethyl-1,3-dioxanes and 2-alkyl-4-methyl-1,3-dioxolanes were the most significant compounds identified in river water and groundwater with a threshold odor of 10 ng/L for 2-ethyl-5,5-dimethyl-1,3-dioxane (2EDD), the most malodorous compound. The analyses were carried out by HRGC/MS, and the synthesized 1,3-dioxanes and dioxolanes were characterized by CI-MS and EI-MS/MS techniques. A company, currently manufacturing saturated and unsaturated polyester resins, located in the upper course of the river, produced these compounds as byproducts during the synthesis of resins. The pollution by dioxanes and dioxolanes affected all the aquifer and slowly diminished to the ppt levels when the company was forced to correctly treat their wastewaters. Additional examples of the presence of dioxanes and dioxolanes in wastewaters of other resin plants and also tap water of Barcelona are shown.
- Romero, Jordi,Ventura, Francesc,Caixach, Josep,Rivera, Josep,Gode, Llui Xavier,Ninerola, Josep Ma.
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p. 206 - 216
(2007/10/03)
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- Method for production of 1,3-dioxolanes
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A method for the production of a 1,3-dioxolane represented by the general formula III: STR1 wherein R1 is hydrogen atom or an alkyl group of 1 to 5 carbon atoms and R2 is hydrogen atom or an alkyl group of 1 to 2 carbon atoms or a phenyl group, which method comprises reacting an aldehyde represented by the general formula I STR2 wherein R1 has the same meaning as defined above, with an alkylene oxide represented by the general formul II: STR3 wherein R2 has the same meaning as defined above, in an alkylene glycol solvent corresponding to said alkylene oxide in the presence of at least one catalyst selected from the group consisting of bromides of alkali metals, iodides of alkali metals, bromides of alkaline earth metals, and iodides of alkaline earth metals.
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- Acetolysis of Cyclic Acetals: Regioselective Acylative Cleavage of Cyclic Formals
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The acid-catalyzed reaction of cyclic acetals with acetic anhydride has been investigated.Acylative cleavage of cyclic formals has been found to be a clean, high-yield reaction involving rupture of the C(2)-O bond with loss of stereochemical integrity at the C(2)-position to give hemiacetal acetate products.Ring cleavage of unsymmetrically substituted cyclic formals with either acetic anhydride or acetyl chloride occurs via preferential rupture of the less congested C(2)-O bond (Scheme I, path A).Such cleavage is totally regiospecific for 1,3-dioxanes and displays high (75-85percent) regioselectivity for smaller and larger ring systems.Acetolysis of cyclic acetals other than formals is a slow process that leads to loss of the aldehyde derived fragment and formation of simple diacetates.These results are rationalized in terms of rate-limiting electrophilic attack that is acutely sensitive to steric effects engendered by substituents located at positions adjacent to ring oxygens.
- Bailey, William F.,Rivera, Alberto D.
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p. 4958 - 4964
(2007/10/02)
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