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Organic Chemistry
Published in Armen S. Casparian, Gergely Sirokman, Ann O. Omollo, Rapid Review of Chemistry for the Life Sciences and Engineering, 2021
Armen S. Casparian, Gergely Sirokman, Ann O. Omollo
Alkenes are used as synthetic precursors for alcohols, polymers, etc. Ethene (C2H4), also known as ethylene, is the simplest alkene. It is a significant factor in plant growth and other transformations such as ripening of fruits, seed germination, and maturation of flowers. Ethene molecules can undergo radical addition reactions to generate polyethylene polymer, also known as polyethene. Table 8.2 lists the first ten alkenes.
Organic Chemistry Nomenclature
Published in Arthur W. Hounslow, Water Quality Data, 2018
Addition Polymers — All addition polymer units are alkenes. Addition polymers are formed by the addition of one polymer unit to another. The final structure incorporates all the atoms of the original structure. The characteristic reaction of alkenes is addition to the double bond, e.g., hydrogen, water, and halogens. If alkene molecules add to the double bonds of each other, an addition polymer is formed, thus (ethylene) nH2C=CH2 ➛ (polyethylene) —(—CH2—CH2—)—n where n may be 1000.
Biomass Chemistry
Published in Jay J. Cheng, Biomass to Renewable Energy Processes, 2017
Alkenes are hydrocarbons that contain at least one double bond between adjacent carbon atoms. The simplest acyclic alkenes contain only one such double bond and have the general formula empirical CnH2n. The simplest examples of such alkenes are ethene (n = 2) and propene (n = 3), shown in Figure 2.4.
Evaluation of performance characteristics of polymer-modified slurry seal (PMSS) by replacing filler with ceramic waste powder
Published in Road Materials and Pavement Design, 2023
Alireza Jalalian Khoshnood, Neda Kamboozia, Hassan Ziari, Mahdi Zalnezhad
FTIR test at wavelengths of 400–4000 was used to investigate the chemical properties of pure bitumen and bitumen containing CWP. The results of the FTIR test for the pure bitumen are given in Figure 3. According to the results and the generated peaks, presence of the peak during the wavelengths of 1376 and 1462 indicates presence of C–CH3 and CH2 bonds of the organic compounds of ethylene and methyl (Ongel & Hugener, 2015; Yang et al., 2015). The presence of the peak with the highest adsorption at 2852 and 2922 wavelengths indicates the presence of C–H bond and the functional group of alkenes. Alkenes are hydrocarbons that have a carbon–carbon double bond (C=C). Also, the presence of peak in the 3419 wavelength indicates the presence of a SiO–H bond of organic amino compounds. Amines are ammonia derivatives and form a wide range of nitrogenous organic substances. Figure 4 shows the results of the FTIR test of CWP materials. Based on the intensity of the peaks at different wavelengths, the presence of peak at 462 wavelength shows the presence of geminal groups in the ceramic powder. The presence of peak at 793 wavelength indicates Si–O bond and the presence of silica. Also, the presence of peak in the 1830 and 3087 wavelengths indicates the Si–O2 bond and the presence of silicon oxide and quartz in the CWP (Hussein et al., 2017).
Research on emissions controlling of coal-made Fischer–Tropsch process diesel/methanol unconventional pollutants
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Hua Xia, Lian Mei, Yang Jiahui
Alkenes are unsaturated hydrocarbons that contain carbon-carbon double bonds. For these molecules, high-energy fluorene bonds are unstable and easy to break, and addition reactions tend to occur. Among olefins, 1,3-butadiene had the highest concentration. Hydrogen atoms and free radicals can easily undergo addition reactions with 1,3-butadiene (Takada, Yoshimura, and Ohga et al. 2003). At idle conditions, 1,3-butadiene were low; compared with the standard operating conditions, at the maximum torque operating conditions, the emissions of the diesel engine were lower, and intermediate products such as 1,3-butadiene stay in the cylinder longer. Such products decompose easily, which reduces their concentrations.
Use of GreenZyme® for remediation of porous media polluted with jet fuel JP-5
Published in Environmental Technology, 2020
Valentinos Loukopoulos-Kousis, Constantinos V. Chrysikopoulos
Jet propellant (JP) fuels are used mainly in military and civilian aircrafts, and consist of relatively complex mixtures of hydrocarbons [33]. Hydrocarbons are composed only of the elements carbon (C) and hydrogen (H) and they are the main constituents of petroleum and natural gas. The hydrocarbons are classified based on their structure into two major groups: aliphatic and aromatic. Aliphatic hydrocarbons are classified based on the types of bonds they contain into: alkanes also called paraffins (contain only single bonds), alkenes also called olefins (contain a carbon–carbon double bond), and alkynes (contain a carbon–carbon triple bond). Aromatic hydrocarbons have unique stability, and they contain one or more planar rings of carbon atoms joined by aromatic (not single) bonds [34]. Alkanes are classified as saturated hydrocarbons (no hydrogen can be added to them), whereas alkenes, alkynes and aromatics as unsaturated hydrocarbons (hydrogen can be added to carbon atoms). The first turbine engines were fueled with plain illuminating kerosine (also spelled as kerosene, which is the general name of paraffin), which was widely available because it was used for wick lamps. Subsequently, after World Was II, the U.S. Air Force developed wide-cut jet fuels, also known as naphtha-type (JP-4) from hydrocarbon mixtures produced by distillation of crude oil. Because these fuels were found to have operational disadvantages due to their high volatility, the Air Force in the 1970s developed kerosine-type jet fuels (JP-8). The U.S. Navy used on aircraft carriers a kerosine-type jet fuel (JP-5) since the 1950s. Also, the commercial jet industry developed in the 1950s kerosine-type jet fuels (Jet A, Jet A-1) balancing performance, fuel price and availability, and (Jet B) for its enhanced cold-weather performance [33]. Several other military fuels are available, which have been developed for highly specific applications. Fuel-soluble chemicals are added to some of the kerosine-type jet fuels in very small amounts to enhance fuel performance and fuel handling. These chemicals are refered to as additives. Furthermore, it should be noted that some military fuels are very similar to their civilian counterparts, containing just different additives.