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Examination of Forensic Evidence
Published in Karen D. Sam, Thomas P. Wampler, Analytical Pyrolysis Handbook, 2021
John M. Challinor, David A. DeTata, Kari M. Pitts, Céline Burnier
Alkyd enamels occurring as original baked enamels or spraying enamels may be identified by the THM pyrolysis derivatization modification of the Py-GC technique [28]. These alkyd polyesters are converted to methyl derivatives of their polyol, polybasic acid, and drying oil. More chemical structure information can be gained from the THM-GC analysis of alkyd resins than from conventional Py-GC. For example, Figure 8.3 shows the THM chromatogram of a blue paint smear found on a crowbar that had been allegedly used to damage a blue automobile. The paint is a baked alkyd enamel. From the THM chromatogram, it is evident that the paint is a pentaerythritol-orthophthalic acid baked alkyd enamel having a coconut non-drying oil crosslinked with a butylated melamine formaldehyde resin.
Natural Oil-Based Polymer: A Sustainable Approach Toward Green Chemistry
Published in Neha Kanwar Rawat, Iuliana Stoica, A. K. Haghi, Green Polymer Chemistry and Composites, 2021
Taruna Singh, Athar Adil Hashmi
Degree of unsaturation of an oil which is measured by calculating the iodine value is the most important factor affecting properties of the oil. Iodine value/ iodine number/ iodine adsorption/iodine index value is the mass of iodine in grams which is consumed by 100 g of an oil or fat. It is used to determine degree of unsaturation in fatty acids. Higher the iodine number, the greater will be the degree of unsaturation in the fat or oil. Depending on their iodine values triglycerides are divided into three categories, that is drying, semi-drying, and nondrying oils. For drying oil, iodine value is higher than 130, for semi-drying oils iodine value range from 90 to 130 while for non-drying oil iodine value is less than 90. Drying power of oil is directly related to the unsaturated nature of oil which on reaction with atmospheric oxygen forms a network. Choice of triglyceride plays an important role in defining the properties of polymer. Coconut oil is very saturated and is used for making soaps while linseed oil is highly unsaturated and is commonly used in the preparation of paints, coatings, inks, and resins.11
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Published in Joseph C. Salamone, Polymeric Materials Encyclopedia, 2020
Castor oil is a non-drying oil extracted from the seeds of the shrub Ricinus Communis (iodine value: 82–90).1,3 A major component of castor oil is ricinoleic acid triglyceride (87%). This fatty acid contains one double bond and a hydroxy group (Scheme II), which can be removed by dehydration. This reaction produces two linoleic acid ester isomers, namely, the 9,11-conjugated and the 9,12-unconjugated structures, as shown in Scheme II. Hence, dehydrated castor oil dries relatively quickly at room temperature. It is slightly more viscous than other drying oils and is used for preparing alkyds and other resins capable of giving glossy films of excellent flexibility with a good adhesion on metals.
Tabebuia rosea: a prospective non-edible biodiesel feedstock
Published in Biofuels, 2022
Sindhuja Sirigeri, K.T. Vadiraj, S.L. Belagali
The degree of unsaturation in an oil is measured by its iodine value. The level of unsaturation corresponds with the number of double bonds in the oil, reflecting its susceptibility to oxidation, which places it in the non-drying groups [17]. The iodine value of T. rosea seed oil is 50.76. This seed oil could be classified as a non-drying oil, since its iodine value is lower than 100 (g I2/100 g sample). Oils with an iodine value of less than 100 (g I2/100 g sample) can be used extensively as lubricants and hydraulic brake fluids. The iodine value obtained here is comparable to the values in the literature for castor and olive oils, which are also non-drying oils [17]. A good drying oil should have an iodine value of 180, as reported by Abayeh et al. [20].
Preparation of jet engine range fuel from biomass pyrolysis oil through hydrogenation and its comparison with aviation kerosene
Published in International Journal of Green Energy, 2019
Zeban Shah, Renato C. Veses, Julio C. P. Vaghetti, Vanessa D. A. Amorim, Rosangela da Silva
Bio-oils consist of more than 300 different organic compounds because of their complex nature. Hence they were divided into six major classes’ monoaromatics, polyaromatics, aliphatic, heterocyclic, oxygenates and nitrogenates which has been previously demonstrated (Junming et al. 2008). The samples were also analyzed by GC-MS (see Figure 4). A total of 71 compounds were identified in pyrolysis oil, considering a minimum signal-to-noise ratio (S/N). The compounds were identified when the similarity between the sample and library spectra was greater than 90% and after a detailed analysis of the spectra. The pyrolysis oil was composed only 5% hydrocarbons (as shown in Table 2) while hydrogenated bio-oil was composed 60% hydrocarbons (as shown in Table 3). In Table 4, the pyrolysis oil and hydrogenated bio-oil compositions are grouped by chemical class alcohols, ketones, ethers, phenols, aromatics and aliphatic hydrocarbons and nitrogen compounds. The pyrolysis oil sample was composed mainly of ketones and nitrogen compounds, with minor amounts of alcohols, ethers and phenols. The most significant compounds in bio-oil are acid (Tetradecanoic acid, Hexadecanoic acid, Octadecenoic acid, etc.) which had combined relative composition of 37%. Out of these Hexadecanoic acid are used to produce soap/cosmetics agent and as non-drying oil for surface coatings (Nurgül et al. 2008).