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Applied Chemistry and Physics
Published in Robert A. Burke, Applied Chemistry and Physics, 2020
Symptoms of most pesticide poisonings are similar. Examples of organophosphate pesticides include malathion, methyl parathion, thimete, counter, lorisban and dursban. The chemical formulas of the organophosphates contain carbon, hydrogen, phosphorus and at least one sulfur atom, and some may contain at least one nitrogen atom. Antidotes are available for organophosphate pesticide poisonings. Many hospitals in rural areas where organophosphates are used by farmers and others will have extra stocks of atropine, which is used to counter the effects of organophosphate pesticides. Carbamate pesticides are derivatives of carbamic acid and are among the most widely used pesticides in the world. Most are herbicides and fungicides, such as 2,4-D, paraquat and dicamba. Carbamate pesticides function in the body by inhibiting nerve impulses. The formula of carbamates contains carbon, hydrogen, nitrogen and sulfur. Examples of carbmates include furadan, temik and sevin.
Chemicals from Non-hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
In the process to produce urea from ammonia (NH3) and carbon dioxide (CO2) (Stamicarbon CO2 stripping Urea 2000 plus Technology), ammonia and carbon dioxide are reacted at 2,100 psi bar to urea and carbamate (a carbamate is an organic compound derived from carbamic acid, NH2COOH). The conversion of ammonia as well as carbon dioxide in the synthesis section results in a low recycle flow of carbamate. Because of the high-ammonia efficiency, no pure ammonia is recycled in this process. The synthesis temperature of 185°C (365°F) is low, and, consequently, corrosion is negligible. Because of the high conversions in the synthesis, the recycle section of the plant is very small. An evaporation stage with vacuum condensation system produces urea melt with the required concentration for the Stamicarbon fluidized bed granulation. Process water produced in the plant is treated in desorption/hydrolyzer section that produces an effluent, which is suitable for use as boiler feedwater. One further step, although not true a nonorganic step is worthy of mention here as a follow on from urea production, and that is the production urea-formaldehyde resins. The chemical structure of the urea-formaldehyde polymer consists of [(O)CNHCH2NH]n repeat units (Chapter 11).
Common Sense Emergency Response
Published in Robert A. Burke, Common Sense Emergency Response, 2020
Carbamate pesticides are derivatives of carbamic acid and are among the most widely used pesticides in the world. Most are herbicides and fungicides, such as 2,4,D, paraquat, and dicamba. Carbamate pesticides function in the body by inhibiting nerve impulses. Carbamates contain carbon, hydrogen, nitrogen, and sulfur. Examples include furadan, temik, and sevin.
Mg/Al/Zr hydrotalcite like compounds as catalysts for green synthesis of carbamates
Published in Inorganic and Nano-Metal Chemistry, 2022
Marwa Aloui, Rihem Dardouri, Salwa B. Ghorbel, Mayra G. Álvarez, Francisco Medina, Mongia S. Zina
Carbamates, which are precursors of polyurethanes, reformal esters resulting from the unstable carbamic acid[7] are worldwide used in various industrial fields including agrochemical chemistry (herbicides, fungicides and insecticides), synthesis of pharmaceuticals, and as intermediates in synthesis of fine and commodity chemicals.[8] However, the traditional route for producing organic carbamates, based on the use of toxic and corrosive phosgene (COCl2) as a C1 synthon. Although, the use of CO2 as a safe substitute for phosgene represents an important benefit for the development of more environmentally benign process because carbon dioxide is a nontoxic, cheap, non inflammable and abundant source of carbon.[2]