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Published in Brajendra K. Sharma, Girma Biresaw, Environmentally Friendly and Biobased Lubricants, 2016
Kenneth M. Doll, Bryan R. Moser, Zengshe Liu, Rex E. Murray
Acrylic and methacrylic acids are of particular interest because their respective polymers have well-established industrial applications. For instance, methyl, ethyl, butyl, and 2-ethylhexyl acrylates are polymerized with several comonomers, including methyl methacrylate, vinyl acetate, styrene, acrylonitrile, and maleic anhydride, to yield commercially important coatings, plastics, adhesives, elastomers, fibers, absorbent materials, polishes, and paints [110,131]. The principal application of methyl methacrylate is homopolymerization to provide poly(methyl methacrylate) (Plexiglas®) as a lightweight and shatter-resistant transparent thermoplastic, which serves as a versatile alternative to glass. It is also an essential component in the polymer dispersion systems of coatings and paints [110,131,132]. Both acrylic and methacrylic acids and their corresponding esters are produced globally on a large scale, each exceeding 3 million metric tons of annual production. In addition, the market for each is projected to increase in coming years, especially in China and India. The rapidly growing construction industry in emerging economies, such as China and India, has propelled the growth of acrylic acid and its derivatives in the Asia-Pacific region. The current market prices for methyl methacrylate and acrylate esters are approximately $1.30/lb and $1.10/lb, respectively. These translate to total market values well in excess of $8 billion annually for each monomer [133,134].
Chemicals from Olefin Hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Methacrylic acid is also produced by the air oxidation of isobutylene or the ammoxidation of isobutylene to methacrylonitrile followed by hydrolysis. Methacrylic acid and its esters are useful vinyl monomers for producing polymethacrylate resins, which are thermosetting polymers. The extruded polymers are characterized by the transparency required for producing glass-like plastics commercially known as Plexiglas.
A comparison of frequency and magnitude of head impacts between Pee Wee And Bantam youth ice hockey
Published in Sports Biomechanics, 2023
Wesley Chen, Andrew Post, Clara Karton, Michael D. Gilchrist, Michael Robidoux, T. Blaine Hoshizaki
A Cadex monorail drop rig was used to reconstruct the head to ice, boards, and glass impact events. The Hybrid III headform and unbiased neckform were secured to a monorail drop carriage and attached to a guided 4.7 m monorail via two linear ball bushings to reconstruct the ice and glass impacts. The headform was placed in a drop carriage and was dropped onto the boards surface without a neck attachment to reconstruct the boards impact. This was done to accurately replicate the location and angle of impacts that are of highest frequency for boards impacts. These impacts were commonly closer to the top of the head and the inclusion of the neck would have prevented the targeting of these locations. This drop carriage was released using a pneumatic piston to drop the headform system onto an anvil consisting of the appropriate impacting surface at the targeted velocities. A metal cylinder anvil filled with water frozen for ≥24 hours at −25°C was used for the head to ice impact reconstructions (Figure 3). An anvil affixed with a cut-out section of high-density polyethylene was used for the head to boards impact reconstructions, placed at both a flat and 45° angle. The head to glass impact reconstructions were conducted with a panel of acrylic glass (Plexiglas). This Plexiglas panel was secured via a wooden frame and placed at a 90° angle relative to the drop carriage at the bottom of the Cadex monorail (Figure 3).
Recent trends in the treatment of cyanide-containing effluents: Comparison of different approaches
Published in Critical Reviews in Environmental Science and Technology, 2023
Ludmila Martínková, Pavla Bojarová, Anastasia Sedova, Vladimír Křen
The products of the cyanation of aldehydes and ketones are cyanohydrins, which are intermediates for fine and pharmaceutical chemicals. For example, mandelonitrile has been obtained by cyanation of benzaldehyde and used to produce mandelic acid (chiral resolving agent, chiral building block). This product is often required in an enantiopure form, such as (R)-mandelic acid, which can be prepared by biocatalytic hydrolysis of racemic mandelonitrile (Martínková & Křen, 2018). (R)-2-Chloromandelic acid can be prepared analogously and is a precursor of the antithrombotic drug clopidogrel (Zou et al., 2021). Cyanation of acetone gives acetone cyanohydrin, a precursor of methyl methacrylate, which is used for the production of polymethyl methacrylate (PMMA) known as, e.g., acrylic or “Plexiglas”.
Effect of surfactant crowding on clathrate hydrate growth
Published in Journal of Dispersion Science and Technology, 2022
Randeep Ravesh, Ayaj A. Ansari, Pradipta K. Panigrahi, Malay K. Das
The experimental set up is illustrated in Figure 1. The experimental set up is designed to facilitate the visualization of droplet using back illumination-based imaging of the droplet. The test chamber contains a cooling jacket made up of plexiglass, which is connected to the constant temperature bath (Julabo F-25 ED, Germany). A thermocouple (K-type) is placed in the reactor to monitor the temperature inside the reactor. The droplet is placed on a glass substrate, which is attached to the Plexiglas stand. The backlight (Apra lights, India) with a rated power of 4 W is used to illuminate the droplet. Photographs are captured using a CMOS Camera (BASLER acA2000 − 165 u mNIR, Germany) equipped with a zoom lens. Spirili CR-01 anti-fog films are pasted on the optical windows to prevent condensation, facilitating imaging at low temperatures.