A review paper of the technology basics of vegetable oils epoxidation by means of peracetic or performic acid in the presence of acidic ion exchange resins has been presented. The infl uence of the following parameters: temperature, molar ratio of acetic acid and hydrogen peroxide to ethylenic unsaturation, catalyst loading, stirring intensity and the reaction time on a conversion of ethylenic unsaturation, the relative percentage conversion to oxirane and the iodine number was discussed. Optimal technological parameters, mechanism of epoxidation by carboxylic peracids and the possibilities of catalyst recycling have been also discussed. This review paper shows the application of epoxidized oils.
A comprehensive review of recent existing methods of epoxidation of vegetable oils, unsaturated
fatty acids and alkyl esters of unsaturated fatty acids has been presented. The importance of
epoxidized vegetable oils and their applications in the production of polyols and polyurethanes was
discussed. Interests of researchers have been mainly focused on the development of advantageous
technological parameters of vegetable oils epoxidation. The epoxidations with peracetic acid or performic
acid generated in situ were mainly performed in the presence of strongly acidic catalysts. The
influence of process variables such as temperature, stirring speed, the molar ratio of carboxylic acid
and hydrogen peroxide to the amount of ethylenic unsaturation, amount of catalyst and reaction time
on the course of epoxidation has been investigated.
This
work aimed to describe the adsorption of volatile organic compound
(VOC) vapor from gas streams onto WG-12 activated carbon modified
with DL-malic acid. The properties of adsorbents were studied by thermogravimetric
(TG) analysis, total acidity, total basicity, and elemental analysis.
The adsorption behaviors of acetone and ethyl acetate for activated
carbons modified with dl-malic acid were investigated at
normal pressure in a fixed bed reactor. Breakthrough curves for each
adsorbate were performed using gas chromatography analysis with a
flame ionization detector. The adsorption capacity of acetone was
within the range of 33–107 mg/g, while that for ethyl acetate
was 61–277 mg/g, which indicated a higher adsorption affinity
of WG-12 toward ethyl acetate. Results showed that the adsorbate molecules
compete for adsorption sites, indicating the occurrence of competitive
adsorption. We also found that the most effective adsorbent for the
tested VOCs is WG-12 modified with dl-malic acid in the amount
of 0.2 g per gram of the unmodified adsorbent and heated at 500 °C.
These results will develop a purification process and reduce volatile
organic compounds’ emissions.
Vegetable oils and their derivatives have great potential as renewable and sustainable raw materials for the production of polyurethanes and bio-based polyols. For industry an important process is their modification. Chemical reactions that are carried out on vegetable oils and their derivatives are: transesterification, auto-oxidation, hydrogenation, epoxidation, hydroxylation, acrylation, isocyanation and others. One of the modifications are reactions performed on double bonds and/or carbonyl moieties of plants oils and their derivatives. These reactions result in products that are actively used as binders in coating materials due to their unique structural properties. In this manuscript, we describe important technological methods for the introduction of hydroxyl groups: opening of oxirane rings by nucleophilic reagents such as: water, alcohols, glycols, amino alcohols, carboxylic acids; direct hydroxylation of unsaturated bonds with carboxylic peracids in combination with hydrolysis of carboxyl groups and hydration; hydroformylation of unsaturated bonds with subsequent hydrogenation and alkoxylation; and ozonolysis of unsaturated bonds in combination with subsequent hydrogenation and alkoxylation.
The influence of addition cleaned granite dust on self-adhesive products, such as self-adhesive tapes based on silicone pressure-sensitive adhesives was presented. The new way of waste management, is a very important issue in the modern world. The obtained self-adhesive materials were tested both in terms of the properties of adhesive compositions (pot-life test) as well as the influence on the operational parameters of the obtained self-adhesive tapes, such as adhesion, cohesion, stickiness or shrinkage. The obtained results are presented in the paper below.
The course of epoxidation of sesame oil (SO) with performic acid formed „in situ” by the reaction of 30 wt% hydrogen peroxide and formic acid in the presence of sulfuric acid(VI) as a catalyst was studied. The most advantageous of the technological independent parameters of epoxidation are as follows: temperature 80°C, H2O2/ C=C 3.5:1, HCOOH/C=C 0.8:1, amount of catalyst as H2SO4/(H2O2+HCOOH) 1 wt%, stirring speed at least 700 rpm, reaction time 6 h. The iodine number (IN), epoxy number (EN), a relative conversion to oxirane (RCO) and oxirane oxygen content (EOe) were determined every hour during the reaction. Under optimal conditions the sesame oil conversion amounted to 90.7%, the selectivity of transformation to epoxidized sesame oil was equal to 93.2%, EN = 0.34 mol/100 g, IN = 0.04 mol/100 g oil (10.2 g/100 g oil), a relative conversion to oxirane RCO = 84.6%, and oxirane oxygen content of EOe = 5.5%.
Six quaternary phosphonium salts (QPSs) in combination with phosphotungstic heteropolyacid, H3PW12O40, were tested in the epoxidation of rapeseed oil fatty acid methyl esters with a hydrogen peroxide aqueous solution. The QPSs consisted of trihexyl(tetradecyl)phosphonium [P6], tributyl-tetradecylphosphonium [P4] or tetraoctylphosphonium [P8] cation and different anions—chloride (Cl−), bromide (Br−), tetrafluoroborate (BF4−), bis(trifluoromethylsulfonyl)amide (NTf2−), bis(2,4,4-trimethyl-pentyl)phosphinate (Phosf−). The influence of the kind of QPS and temperature on the epoxy number, iodine number, glycol content has been determined. The epoxidation was confirmed using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) and elemental analysis CHO. Two QPSs with a trihexyltetradecyphosphonium cation—[P6][Fosf] and [P6][Cl]—were selected as the most effective in the studied epoxidation process. The proposed kinetic model takes into consideration the two reactions, namely, epoxidation and epoxy ring opening involving the formation of hydroxyl groups. The rate constants and activation energies for epoxidation fatty acid methyl esters were determined.
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