Glycidyl Esters Research Articles

Synthesis of Acrylic Copolymers with Pendant Hydrophilic Groups and Comparative Surface Tension Studies with Corresponding Siloxane Copolymers

Methyl methacrylate (MMA) and methacrylic acid glycidyl ester (MAGE) have been copolymerized and three water-soluble derivatives of these types of copolymers have been synthesized by opening the epoxide ring with different hydrophilic functional groups like diethanolamine (CHE), quaternary diethylamine (CQDEA) and quaternary diethanolamine (CQHE) The structures have been identified by 1 H and 13 spectra. The behaviors in aqueous medium have been investigated in terms of the surface tension and the ratios of intensities of the fluorescence (I 1 /I 3 ). The results are compared with those of the corresponding water-soluble siloxane copolymers (SHE, SQDEA, SQHE). The plot of I 1 /I 3 as a function of polymer concentration verifies the existence of aggregates and indicates the extent of aggregate formation. It is found that the polymer molecules begin to transfer to the air/water interface before they start to form aggregates for both acrylic and siloxane copolymers. It is evident from the surface tension measurements that efficiency of these polymers to reduce surface tension in aqueous solution is in the order SHE > SQHE > SQDEA and CHE > CQDEA > CQHE. The plots of I 1 /I 3 as a function of polymer concentration show that the ease of formation of aggregates in aqueous solutions of the above-mentioned polymers is in the order SHE > SQDEA > SQHE and CHE >CQDEA > CQHE. The ability of aggregates formation in aqueous solution increases with increasing polymer concentration and the hydrophilicity of the hydrophilic moieties. Moreover, the inner core of these copolymer aggregates is less closely packed than those for usual surfactants like sodium dodecylsulfate (SDS). However, the inner cores of the aggregates of siloxane copolymers in solution are more hydrophobic than those of acrylic copolymers.

Modification of epoxy binders for glass-and basalt-reinforced plastics

The process parameters of production of epoxy binders modified with glycidyl esters of phosphorus acids were studied, and the performance characteristics of glass- and basalt-reinforced plastics on their basis were determined.

Enantioselective enzymatic hydrolysis of racemic glycidyl esters by using immobilized porcine pancreas lipase with improved catalytic properties

The crude porcine pancreas lipase (PPL) extract is a mixture of several proteins (mainly lipases and esterases). In order to develop enzymatic catalysts with good catalytic properties for hydrolytic enantioselective reactions in aqueous homogeneous medium, we studied the immobilization of the different enzymes contained in the crude PPL extracts by selective sequential adsorption on hydrophobic supports bearing octyl, octadecyl and phenyl groups. Some minor proteins were selectively adsorbed on octyl and octadecyl supports while the most abundant lipase was adsorbed on the support bearing phenyl groups. The enantioselectivity of the different lipase derivatives were tested considering the hydrolysis of esters of 1,2-epoxi-1-propanol (glycidol). The most abundant lipase contained in the commercial crude PPL extract resulted almost inactive while some lipases contained in low concentrations displayed high activities and enantioselectivities. The most interesting results were obtained with a 28-kDa protein selectively adsorbed on octyl-agarose. With this enzyme derivative, the residual butyric ester of glycidol was recovered with 96% enantiomeric excess at 55% conversion.

Substituent effect on the cationic ring-opening polymerization of acyloxymethyl five-member cyclic dithiocarbonates

Five-member cyclic dithiocarbonates were synthesized by the reactions of carbon disulfide with benzoic, p-anisic, p-chlorobenzoic, 1-naphthalenecarboxylic, p-nitrobenzoic, and p-(tert-butyl)benzoic glycidyl esters, and their cationic ring-opening polymerizations were carried out with methyl trifluoromethane sulfonate and trifluoromethane sulfonic acid as initiators at room temperature to 80°C. Polymers with number-average molecular weights of 3400-24,900 were obtained in high yields, and their structures were estimated by NMR and IR spectroscopy. The monomers showed a clear difference in the polymerization rate according to the substituents. The rate of polymerization decreased in the order of p-chlorobenzoic ≥ benzoic > 1-naphthalenecarboxylic > p-nitro-benzoic > p-tert-butylbenzoic > p-anisic. The data of the reaction kinetics, NMR studies, and molecular orbital calculations proved a plausible mechanism involving the participation ofp-substituted benzoyloxymethyl groups to stabilize the cationic propagating end. The polymers showed decomposition temperatures with 5% weight loss ranging from 200 to 260 °C. No glass-transition temperatures for the polymers were observed below 200 °C by differential scanning calorimetry.

Epoxy Polymers Modified with Glycidyl Esters of Phosphorus Acids

The softening point, heat and fire resistance, oxygen index, flammability, and smokiness of epoxy polymers modified with glycidyl esters of phosphorus acids were evaluated, and compression and bending tests of these materials were performed.

Heating of food and haemoglobin adducts from carcinogens: possible precursor role of glycidol

Studies of adducts from reactive compounds to haemoglobin (Hb) by gas chromatography–tandem mass spectrometry according to the N-alkyl Edman method reveals the occurrence of N-(2,3-dihydroxypropyl)valine (diHOPrVal) at levels of 1–2 pmol/g Hb, in persons without known exposure. The hypothesis that this background originates from glycidol or related compounds during heating of food was tested in experiments with rats. Animals fed fried animal feed for 30 or 72 days showed an increase of the diHOPrVal level by about 50% compared with controls. Several arguments, such as the formation of reactive oxiranes by heat-induced dehydration of glycol configurations in glycerol and sugars, support the idea that glycidol (or e.g. glycidyl esters) are precursors of the adduct. In Hb samples, reduced for stabilisation of aldehyde adducts, relatively high levels of adducts determined as diHOPrVal were found, although without significant relation to frying of the feed. There is thus no indication that reduction in vivo of, for example, the Schiff base from glyceraldehyde, is a pathway for formation of the diHOPrVal. The background level of diHOPrVal in humans Hb is low, and the cancer risk associated with exposure to the specific alkylator—probably glycidol—formed in cooking, is therefore presumably low. The result implies, however, that low-molecular mass mutagenic oxiranes formed during the heating of food should be studied further.

Acids and their functionally substituted esters fromAmaranthus cruentus seed oil

The acid composition of seed oil ofAmaranthus cruentus and the synthesis of their glycidyl and pyridinecontaining esters are studied. It is demonstrated that 67% of the total acids are C18-polyunsaturated linoleic and linolenic. A new method for preparing glycidyl esters of C18-unsaturated carboxylic acids is developed by reacting their salts with ECG in an aprotic medium to produce the corresponding glycidyl esters. The reaction of the glycidyl esters and pyridine salts with carboxylic and phosphonic acids produces the propanolpyridine esters of the acids that combine the properties of the acids and pyridinium salts and are promising in the search for biologically active compounds.

Novel Synthesis And Enzymatic Resolution of (±) -2,3 - Epoxy Propyl Esters

A novel method of synthesizing glycidyl esters (±) -2,3-epoxy propyl esters has been developed involving reaction of epichlorohydrin with sodium salt of carboxylic acids in the presence of 15-crown-5 as catalyst with excellent yields. Enzymatic resolution of these glycidyl esters by lipasePS-C has been achieved with remarkable substrate selectivity.

Determination of dimers concentration of chromophores by the method of fluorescence synchronous scanning

In order to determine the concentration ratio of monomers to dimers of a fluorescent chromophore in a polymer matrix we have applied fluorescence synchronous scanning. We have studied compositions poly(methyl methacrylate) with (9-anthryl)glycidyl ester and have estimated the share of aggregated chromophore and the efficiency of radiationless energy transfer from monomers to dimers.

Metabolic inactivation of 2-oxiranylmethyl 2-ethyl2,5-dimethylhexanoate (C10GE) in skin, lung and liver of human, rat and mouse

1. The inactivation of 2-oxiranylmethyl 2-ethyl-2,5-dimethylhexanoate (C10GE), one of the most abundant isomers of the epoxy-resin Cardura®E-10 glycidyl ester, was studied in subcellular fractions of human, C3H mouse and F344 rat liver, lung and skin. 2. C10GE is chemically very stable and resistant to aqueous hydrolysis, but it was rapidly metabolized in both cytosolic and microsomal fractions of all organs by epoxide hydrolase (EH)-catalysed hydrolysis of the epoxide moiety as well as carboxylesterase (CE)-catalysed hydrolysis of the ester bond. In cytosol the epoxide group was also efficiently conjugated with glutathione, catalysed by glutathione S-transferase (GST), but this conjugation was much less important than hydrolysis in human as well as rodent samples. Although CE-catalysed hydrolysis of C10GE would theoretically give rise to the formation of glycidol, a directly acting mutagen, it is highly unlikely that any significant level of glycidol would occur in vivo since reported rates of inactivation of glycidol exceed the total rate of hydrolysis of C10GE. 3. The overall rates of inactivation in vitro decreased in the following order: mouse > rat > human. Scaling of the data in vitro to clearances in vivo suggests that the detoxifying capacity in the rodents is similar and about an order of magnitude greater than in human. Nevertheless, the rate of inactivation is 2-3 orders of magnitude greater than for simple epoxides such as butadiene monoxide and about one order of magnitude higher than for the diglycidyl ether of bisphenol A (BADGE). 4. The transdermal penetration and metabolism of [14C]-C10GE was studied in fresh full-thickness mouse, and dermatomized human and rat skin. Of the total radioactivity applied on the skin, only 0.24±0.06 (SD), 1.8±0.2 and 6.8±0.6% penetrated through human, mouse and rat skin respectively. The corresponding apparent skin permeability constants were 0.81, 6.42 and 26.4X 10−6 cm/h. 5. During transdermal penetration, [14C]-C10GE was extensively hydrolysed to the corresponding diol and the free acid. Only 0.01, 0.11 and 0.21% of the applied dose was absorbed unchanged through the human, mouse and rat skin respectively.

5532163 Process for refining oil and fat: Yagi Takashi; Higurashi Masakaz; Tsuruoka Hiroka; Nomura Isao, Chiba, Japan assigned to Showa Sangyo Co Ltd

Corresponding the high presence of 3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters (GE) in refined palm oil, this paper re-evaluated degumming and bleaching processes of physical palm oil refining to reduce the amount of said contaminants. Separation-free water degumming was incorporated into the process, and this significantly (p < 0.05) reduced the esters content without compromising other oil qualities. Different types of bleaching earth (BE) were dosed at 0.5, 1.0 and 1.5% to investigate their effects on the esters formation. Results showed that different type of BE had their own optimal dosage for minimum esters formation. Surface acidity was confirmed as the key performance determinant of BE in mitigation of 3-MCPDE and GE in oil rather than the porosity profile. Specifically, BE with high acidity should be avoided, but slightly acidic BE (pH ≃ 5) was found to provide the greatest reduction of esters as compared to natural and neutral activated BE.

Chain extension of polyesters PET and PBT with N,N′‐bis (glycidyl ester) pyromellitimides. I

AbstractThree N,N′‐bis (glycidyl ester imide) of pyromellitic acid (diepoxides) were prepared and were used as chain extenders for poly (ethylene terephthalate) (PET) and poly (butylene terephthalate) (PBT). The typical reaction conditions for the coupling of the polyester macromolecules were heating with the chain extender under argon atmosphere above the melting temperature (280°C for PET and 250°C for PBT) for several minutes. The Characterization of the samples, obtained at variable residence times in the reactor, was based on solution viscosity measurements and carboxyl and hydroxyl end‐group determinations. Two of the diepoxides used gave satisfactory results. Starting from a PET having intrinsic viscosity [η] = 0.60 dL/g, and carboxyl content CC = 42 eq/106 g, one could obtain PET with [η] = 1.15 dL/g and CC = 16 eq/106 g within 30 min at 280°C. Analogous results were observed for PBT. The hydroxyl content of polyester in all cases was increased. When the quantity of the chain extender used was higher than that theoretically required for its reaction with all carboxyl end groups of the polyester, this resulted in some gel formation indicative of crosslinking. © 1995 John Wiley &amp; Sons, Inc.

Polymères porteurs de dérivés du glycérol, 10. Fixation de l'acide naphtyl‐1 acétique sur le poly(acide méthacrylique)

Glycidyl (2,3-epoxypropyl) esters are convenient reagents for the fixation of carboxylic acid moieties on polymeric support of the polyacid type. This way of synthesis was applied to 1-naphthylacetic acid on poly(methacrylic acid). Esterification of 1-naphthylacetyl chloride by glycidol (2,3-epoxy-1-propanol) and addition of 1-naphthylacetic acid on epichlorohydrin (1-chloro-2,3-epoxypropane) with subsequent reformation of the oxirane ring have been used for the synthesis of the glycidyl ester but the reaction of the potassium salt of the acid with epichlorohydrin leads to a better yield. Addition of 1-naphthylacetic acid on glycidyl acetate was studied in N,N-dimethylformamide (DMF) and acetonitrile. The best results were obtained in DMF. The reaction is of first order with respect of epoxide, but 2nd order applies when the solvent is acetonitrile. The same reaction conditions as for glycidyl acetate were used for the chemical modification of poly(methacrylic acid) with glycidyl 1-naphthylacetate except that methanol was used as the solvent.

Methods for the determination of the enantiomeric purity of the C 3-synthons glycidol (2,3-epoxy-1-propanol) and solketal [2,2-dimethyl-4-(hydroxymethyl)-1,3-dioxolane

Accurate and reliable methods are presented for the determination of enantiomeric excess values of glycidol (2,3-epoxy-1-propanol), glycidyl esters, solketal [2,2-dimethyl-4-(hydroxymethyl)-1,3-dioxolane], homologous 1,3-dioxolane alcohols and substituted primary propanols in biological samples. One method consists of derivatization of the samples with 2,3,4,6-tetra-O-acetyl-β-glucopyranosyl isothiocyanate, followed by separation of the resulting diastereomers on a non-chiral reversed-phase (C 18) HPLC column. The second method uses direct injection of (aqueous) samples on to capillary GC columns coated with chiral stationary phases (2,3,6-tri-O-methyl-β- or a 2,3,6-tri-O-trifluoroacetyl-λ-cyclodextrin). The advantages and disadvantages of both methods are discussed.

New epoxy‐terminated oligoesters: Precursors to totally biodegradable networks

AbstractTwo types of novel biodegradable epoxy resins, carrying cycloaliphatic‐epoxy and glycidyl ester end‐groups, have been synthesized from hydroxy‐telechelic oligoesters. The cycloaliphatic‐epoxy end‐groups were based on either methyl cis‐4‐cyclohexene‐2‐(carboxylic acid)‐1‐carboxylate or 3‐cyclohexene‐1‐carboxylic acid. These compounds were reacted with hydroxy‐telechelic poly(ε‐caprolactone‐co‐D,L‐lactide) oligoesters, yielding cycloaliphatic‐olefin‐terminated oligomers. Conversion of the olefin to the epoxide groups was achieved using a phase transfer epoxidation with an inorganic peracid derived from the reaction of phosphoric acid, sodium tungstate, and hydrogen peroxide. Aliquat 336, a quaternary ammonium salt, acted as the phase transfer catalyst. Nearly theoretical conversion of hydroxy to epoxy end‐groups was achieved in only one case, however, alternative variations of this method of synthesis show promise. To prepare glycidyl ester‐terminated prepolymers, hydroxy‐telechelic poly(ε‐caprolactone) oligoesters were reacted with succinic anhydride, in 1,2‐dichloroethane with 1‐methylimidazole as catalyst, resulting in (carboxylic acid)‐terminated oligomers. After conversion of the end‐groups to the potassium carboxylate salt by titration with methanolic KOH, the isolated salt was dried and reacted with epibromohydrin in acetonitrile at reflux, using an 18‐C‐6 crown ether as the phase transfer catalyst, thus preparing the (glycidyl ester)‐telechelic prepolymer. Epoxide equivalent weights differed by 2.7–7.1% from the theoretical values. These cycloaliphatic‐epoxide and glycidyl ester‐terminated prepolymers may be crosslinked with anhydrides or amines, respectively, to produce totally bioabsorbable networks. © 1993 John Wiley &amp; Sons, Inc.

Enzymatic and chromatographic chiral discrimination of racemic (thio)glycidyl esters: Part II. Optical resolution of racemic (thio)glycidyl esters on modified cellulose chiral stationary phases

AbstractChiral chromatography on cellulose tris(3,5‐dimethylphenyl carbamate) (Chiralcel OD) and cellulose tribenzoate (Chiralcel OB) coated stationary phases has been successfully used for the optical resolution of rac‐(thio)glycidyl esters (acetate, propionate, butyrate). Glycidyl esters could sufficiently be resolved on the OD column whereas for the thio analogues baseline resolution is obtained on CSP OB using hexane/2‐propanol mobile phases. The separation factor (α) and resolution (RS) depend on column temperature, eluent composition, and flow rate, respectively. Best results were obtained for the butyrates and at low temperatures in general. © 1993 Wiley‐Liss, Inc.

Glycidyl Esters of Phthalic Acid as Plasticizers and Stabilizers for PVC

AbstractMono‐ and di‐glycidyl esters of phthalic acid were tested as plasticizers and stabilizers for PVC. These were compared with commercial products, such as dibutylphthalate, di‐2‐ethylhexyl‐phthalate, epoxydized soyabean oil and glycerine monooleate. The glycidyl esters of mono‐alkylphthalates exhibited, at lower temperature levels, a better solubility for PVC than di‐2‐ethylhexyl‐phthalate. n‐Octyl‐ and 2‐ethyihexyl‐glycidyl‐phthalate are better than di‐2‐ethylhexyl‐phthalate w.r.t. plastcizing and gelatinizing characteristics. Mixture of PVC with either of the two glycidyl esters exhibited also higher thermal stability than diethylhexyl‐phthalate‐PVC‐mixture. n‐Octyl‐ and 2‐ethylhexyl‐glycidyl‐phthalate are comparable with glycerinmonooleate as PVC‐co‐stabilizer. However, they are as stabilizers inferior to epoxydized soyabean oil. The glycidyl esters exhibit a higher volatility compared to diisooctyl‐phthalate, whereas, this is in the case of dibutylphthalate lower. Diglycidylphthalate is in contrast to alkylglycidylphthalates unstable above 130°C so that it is not suitable as PVC‐plastizicer.

Enzymatic and chromatographic chiral discrimination of racemic (thio)glycidyl esters: Part I. A chemoenzymatic approach to both enantiomers of thioglycidyl esters

AbstractBoth hitherto unknown (+)‐(R)‐ and (−)‐(S)‐thioglycidyl esters, (R)‐(2) and (S)‐(2), have been synthesized with different high enantiomeric excesses (ee) by two routes from the corresponding rac‐glycidyl esters rac‐(1). The first includes a porcine pancreatic lipase (PPL)‐mediated kinetic resolution of these esters followed by sulfuration with practically complete inversion to the (+)‐(R)‐enantiomer (+)‐(R)‐(2) (36–86% ee). (−)‐(S)‐Thioglycidyl esters (−)‐(S)‐(2) are obtained by the reverse reaction sequence (43–80% ee). In the latter case the hydrolysis rate is lower than that of analogous glycidyl esters. Moreover, the dependence of enantiomeric excess on the size of the acyl‐group is of the opposite tendency. Therefore, in both cases suitable selection of the acid residue gives rise to maximum enantioselectivity. The irreversible lipase‐catalyzed acylation of rac‐glycidol and rac‐thioglycidol, however, was found to be a less suitable alternative. The enantiomeric excess of recovered homochiral esters was determined by chiral chromatography using modified cellulose stationary phases (OB, OD). © 1993 Wiley‐Liss, Inc.

A Novel Method for Preparation of Glycerol Monoesters from Glycidyl Esters with Molecular Oxygen Catalyzed by Ni(II) Complex

Abstract In the presence of a catalytic amount of bis(3-methyl-2,4-pentanedionato)nickel(II) (Ni(mac)2), various glycidyl esters are converted into the corresponding glycerol monoester derivatives with molecular oxygen in good to high yields.

A short highly regio- and stereoselective synthesis of triacylglycerols

Glycidyl esters reacted with carboxylic anhydrides in the presence of LiBr in tetrahydrofuran (THF) or benzene to produce 3-bromo-1,2-propanediol esters with no significant acyl migration. Displacement of Br by cesium carboxylates was accomplished cleanly in THF-hexamethylphosphoric triamide (THF-HMPT) at 50–55°C (5 h) completing a highly regioselective triglyceride synthesis. The regioselectivity of these reactions allows stereoselective synthesis if one initiates the short sequence with enantiomerically pure glycidol. Commercial ( R)-(+)-glycidol (94.6% R) was used to synthesize ( R)- and ( S)-lauroyl oleoyl palmitoyl glycerol. 1H-NMR data of S-methoxy- α-trifluoromethylphenyl acetic acid (( S)-MTPA) derivatives formed by reaction of the (S)-MTPA ester of ( R)-glycidol indicated that these reactions preserved configuration as expected.