Preparation of Acrylic and Methacrylic Acids by Pyrolysis of Their Alkyl Esters

Ratchford, William P.; Rehberg, C. E.; Fisher, C. H.

doi:10.1021/ja01239a016

Cited by 21 publications

(7 citation statements)

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“…The ester group can also generate carboxylic acid through ester pyrolysis. However, this reaction generally occurs above 500 °C . At this temperature, the relative reactants are already gasified.…”

Section: Resultsmentioning

confidence: 99%

Ultralow-Fouling Zwitterionic Polyurethane-Modified Membranes for Rapid Separation of Plasma from Whole Blood

et al. 2021

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The separation of plasma from blood cells in whole blood is an essential step for many diagnostic and therapeutic applications. However, the current point-of-care plasma separation approaches have not yet satisfied the need for a rapid, high-flux, and low-cost process. Here, we report a portable, low-cost, disposable membrane-based plasma separation device that enables rapid plasma extraction from whole blood. Rapid separation of plasma can be obtained with a simple three-step operation: blood injection, separation, and plasma collection. Our device benefits from the zwitterionic polyurethane-modified cellulose acetate (PCBU-CA) membrane, which can greatly inhibit the surface fouling of blood cells and membrane flux decline. The zwitterionic coating is stable on the membrane surface during blood filtration and leads to a 60% decrease in surface fibrinogen adsorption than a nonmodified membrane surface. The ultralow-blood-fouling properties of the PCBU-CA membrane enable rapid, continuous separation of plasma: within 10 min, the device can yield 0.5−0.7 mL of plasma from 10 mL of whole blood. The extracted plasma is verified as cell-free, exhibits a low hemoglobin level, and has a high protein recovery. Our PCBU-CA membrane provides a pathway for developing a high-efficiency portable plasma separation device that can reduce the time to diagnosis, allow effective patient care, and eventually reduce hospital costs.

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Section: Resultsmentioning

confidence: 99%

Ultralow-Fouling Zwitterionic Polyurethane-Modified Membranes for Rapid Separation of Plasma from Whole Blood

et al. 2021

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“…The rst encounter of LA usage to produce AA is found in a 1935 paper 78 by Burns et al and this was followed in the 1940s with papers by Fisher and co-workers [79][80][81][82][83] and a patent led in 1949 by Atwood. 84 Generally, an alkyl lactate is converted into its corresponding alkyl acrylate via pyrolysis of an alkyl 2-acetoxypropionate intermediate with the formation of acetic acid as a by-product.…”

Section: Dehydration To Acrylic Acidmentioning

confidence: 99%

Lactic acid as a platform chemical in the biobased economy: the role of chemocatalysis

Dusselier

Wouwe

Dewaele

et al. 2013

Energy Environ. Sci.

708

620

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Upcoming bio-refineries will be at the heart of the manufacture of future transportation fuels, chemicals and materials. A narrow number of platform molecules are envisioned to bridge nature's abundant polysaccharide feedstock to the production of added-value chemicals and intermediate building blocks. Such platform molecules are well-chosen to lie at the base of a large product assortment, while their formation should be straightforward from the refined biomass, practical and energy efficient, without unnecessary loss of carbon atoms. Lactic acid has been identified as one such high potential platform. Despite its established fermentation route, sustainability issueslike gypsum waste and cost factors due to multi-step purification and separation requirementswill arise as soon as the necessary orders of magnitude larger volumes are needed. Innovative production routes to lactic acid and its esters are therefore under development, converting sugars and glycerol in the presence of chemocatalysts. Moreover, catalysis is one of the fundamental routes to convert lactic acid into a range of useful chemicals in a platform approach. This contribution attempts a critical overview of all advances in the field of homogeneous and heterogeneous catalysis and recognises a great potential of some of these chemocatalytic approaches to produce and transform lactic acid as well as some other promising a-hydroxy acids. Broader contextLactic acid is one of the top biomass derived platform chemicals, with a promising role in future bio-reneries. A wide range of catalytic transformations of lactic acid are feasible leading to the selective production of green solvents, ne chemicals, commodity chemicals and fuel precursors. Even more appealing is its role as the precursor for biodegradable PLA (polylactic acid) polymers. These polyesters have the potential to replace fossil derived plastics in particular applications, and based on life cycle analyses, they have a more positive impact on the environment. PLA can also be used in vivo and in biomedical applications. The demand for PLA and green solvents is growing and stresses the current fermentative production of lactic acid, which suffers from up-scaling and environmental issues due to concerning waste co-generation and purication steps. Novel chemocatalytic routes are under development to obtain pure lactic acid or esters directly from sugar feedstock. These mainly heterogeneous catalytic processes have potential and could lie at the heart of an evolution in lactic acid research. Once lactic acid is available at competitive prices, its use as a feedstock in a platform approach could become commercially viable, thereby providing renewable and CO 2neutral alternatives for fossil derived chemicals.

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“…Much the same value was also archivally chosen [7,8] using an understanding of rather disparate ''ancient'' values [9,10]. Recently, enthalpy of vaporization values of 57.3 [5] and 53.1 [6] kJ mol -1 have been reported while an early one of 46.9 [11] kJ mol -1 was recommended [12]. Putting all of the values together we find a 16 kJ mol -1 spread of values of the enthalpy of formation of gaseous acrylic acid to choose among: even ignoring ''old ''values, the range is still 12 kJ mol -1 , namely ca.…”

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confidence: 99%

What is the enthalpy of formation of acrylic acid?

et al. 2007

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Acrylic acid is a key industrial compound with numerous uses. Despite its importance, its enthalpy of formation is still contentious-even ignoring ''ancient'' determinations, there is a 12 kJ mol -1 range of values reported for the gas phase quantity, -320 to -332 kJ mol -1 . Our quantum chemical calculations using current methodology suggest the value of -321 ± 3 kJ mol -1 .Keywords Acrylic acid Á Chemical industry Á Enthalpy of formation Á Entropy Á Gibbs energy of formation Á G2 and G3 quantum chemical calculations Á Polymers Á Propenoic acid Á Rotamers Acrylic acid (propenoic acid) is a key industrial compound. Historically, the polymerizable monomer has been manufactured by the hydrolysis of ethylene cyanohydrin (b-hydroxypropionitrile), by a Reppe process involving carbon monoxide addition to acetylene, by the reaction of formaldehyde with ketene, and by the hydrolysis of acrylonitrile. Today, acrylic acid is produced commercially by gas phase oxidation of propylene over heterogeneous catalysts [1]. Acrylic acid is used [2] in the production of superabsorbent polymers, detergents, and water treatments. The various esters of acrylic acid are converted into acrylic polymers and copolymers that are used in a wide variety of products including architectural and industrial paints, coatings, floor polishes, adhesives, caulks, sealants, plastics additives, and dispersants. As evidence of its commercial importance, in 2004, global production capacity of acrylic acid [3] was about 9 billion lbs (ca. 4 · 10 6 tons or 4 · 10 9 kg) of which about three-quarters was for captive (i.e., intra-company, as opposed to merchant, inter-company) uses. Demand growth has been averaging slightly better than GDP and selling prices has averaged ca. $0.85 per pound (1.4 e/kg) on the American market, and somewhat higher on the European and Asian markets.Acrylic acid is also the simplest unsaturated carboxylic acid and as such, is both an archetype of functionalized olefins and of carboxylic acids alike. Acrylic acid is additionally a conceptually simple example of a conjugated bifunctional species.Despite the considerable economic and conceptual importance of acrylic acid, its enthalpy of formation is still contentious-even ignoring ''ancient'' determinations, there is a 12 kJ mol -1 range of values for the gas phase quantity. Presenting chronologically and without bias, there is an earlier seemingly reliable determination of -383.8 ± 0.9 kJ mol -1 [4] arising from the analysis of liquid phase hydrogenation calorimetry measurements. We also find recent values for the enthalpy of formation in the liquid phase: -377.8 ± 9.3 [5] and -383.8 ± 2.0 [6] kJ mol -1 , arising from the combustion of a freshly distilled sample of unstated purity and of one contaminated by acetic acid and an added polymerization inhibitor. Much R. Notario (&) Á M. V. Roux

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Preparation of Acrylic and Methacrylic Acids by Pyrolysis of Their Alkyl Esters

Cited by 21 publications

References 0 publications

Ultralow-Fouling Zwitterionic Polyurethane-Modified Membranes for Rapid Separation of Plasma from Whole Blood

Ultralow-Fouling Zwitterionic Polyurethane-Modified Membranes for Rapid Separation of Plasma from Whole Blood

Lactic acid as a platform chemical in the biobased economy: the role of chemocatalysis

What is the enthalpy of formation of acrylic acid?

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