Showing papers on "Transesterification published in 1976"
TL;DR: In this paper, the most important reaction is the introduction of acids of low mol wt into a fat with higher fatty acids, the so-called transesterification which in recent years has taken on the same importance as hydrogenation or fractionation.
Abstract: Types of interesterification discussed are (a) interchange between a fat and free fatty acids, in which the most important reaction is the introduction of acids of low mol wt into a fat with higher fatty acids; (b) interchange between a fat and an alcohol, e.g., with glycerol, in order to produce emulsifiers like monoglycerides; (c) rearrangement of fatty acid radicals in triglycerides, the so-called transesterification which in recent years has taken on the same importance as hydrogenation or fractionation. In natural fats, the fatty acid radicals are not usually randomly distributed but become so by rearrangement; the distinctive physical properties of natural fats and oils can be changed within limits by this transesterification. Well-known examples are cocoa butter, palm oil, and lard. More important is the transesterification of a mixture of different fats and oils; e.g., the combination of hydrogenation and interesterification allows the production of a solid fat with high linoleic acid content. The composition of glycerides after random interesterification can be calculated by formulas. Distinct from random is such directed interesterification. This is done by working at low temperatures that glycerides with higher melting point crystallize from the reaction mixture. Directed interesterification can be combined with fractionation, for instance, to get a higher yield of liquid fraction from palm oil than is obtained by fractionation alone. The transesterification process can be performed in a batch or continuously. A small amount of metallic sodium or sodium ethylate is used as catalyst, which is destroyed by water or acid and removed after the reaction.
43 citations
TL;DR: The thermal stability of poly-ϵ-caprolactone samples obtained by ring-opening polymerization in the presence of different metal alkoxides has been investigated in this article.
Abstract: The thermal stability of poly-ϵ-caprolactone samples obtained by ring-opening polymerization in the presence of different metal alkoxides has been investigated A significant degradation of the polyesters is observed under isothermal conditions at 120°C The degradation is related to the nature of the endgroup, the presence of catalyst residues, and the presence of molecular oxygen The hydroxyl endgroups play a determinant role in the process They probably give rise, under the influence of catalyst residues, to hydroperoxides which are responsible for the polymer degradation by a radical reaction It is shown that this is clearly different from the change in molecular weights distribution due to the well-known ester interchange reaction (transesterification equilibrium) Resulting methods for the polymers stabilization are indicated
22 citations
TL;DR: In this article, N-substituted derivatives of 5-aza-2,8-dioxa-1-stannocyclooctane, which is a heterocyclic compound of tin(II), have been synthesized in high yields by transesterification of dimethoxy- or di-n-butoxytin(II) with di-ethanolamines.
Abstract: N-substituted derivatives of 5-aza-2,8-dioxa-1-stannocyclooctane, which is a heterocyclic compound of tin(II), have been synthesized in high yields by transesterification of dimethoxy- or di-n-butoxytin(II) with di-ethanolamines. All the compounds are monomers in the vapor phase and the soluble species are associated to some degree in chloroform solution.
17 citations
Patent•
03 May 1976TL;DR: In this article, a trialkylhydroxyphenylalkanoic acid has been used as stabilizer for organic materials, especially polyolefins, which deteriorate upon exposure to light and heat.
Abstract: The compounds are esters and amides of trialkylhydroxyphenylalkanoic acid having the formula ##STR1## WHEREIN R, R 1 and R 2 are independently lower alkyl or cycloalkyl groups, R 3 is hydrogen, alkyl, cycloalkyl, alkylene, phenyl, phenyl substituted by alkyl groups, alkylthioethyl, thiobis-alkylene, alkyleneoxyalkylene, polyoxyalkylene or a polyvalent cyclic or acyclic hydrocarbon radical, R 4 is hydrogen, lower alkyl, cycloalkyl, R 5 is hydrogen, alkyl, phenyl, phenyl substituted with alkyl groups, alkylene, polyoxyalkylene or polyvalent cyclic or acyclic hydrocarbon radical, A is lower alkylene, m is 1 to 4 and n is 1 to 6. The ester compounds of this invention are prepared via usual esterification procedures from a suitable alcohol and an acid of the formula I ##STR2## or an acid halide or acid anhydride thereof. The higher alkyl esters can also be prepared from the lower alkyl ester, especially the methyl ester of the above represented compounds, by transesterification with a higher alkanol. The amide compounds of this invention are prepared by usual amidation procedures by reacting a carboxylic acid of formula I or an acid chloride or anhydride or a lower alkyl ester thereof with the appropriate amine. The compounds are useful as stabilizers for organic materials, especially polyolefins, which deteriorate upon exposure to light and heat.
14 citations
Patent•
28 Oct 1976
TL;DR: Carboxylic acids may be esterified by reaction with esters in the presence of a catalytic amount of a tin halide catalyst, the reaction being effected at temperatures ranging from about 0° to about 150° C as mentioned in this paper.
Abstract: Carboxylic acids may be esterified by reaction with esters in the presence of a catalytic amount of a tin halide catalyst, the reaction being effected at temperatures ranging from about 0° to about 150° C.
14 citations
TL;DR: In this paper, eight cyclic phosphonates and thiophosphonates of the type have been synthesized by the Arbuzov rearrangement or by normal esterification or transesterification procedures and their chemical and spectral properties have been determined.
Abstract: Eighteen cyclic phosphonates and thiophosphonates of the type have been synthesized by the Arbuzov rearrangement or by normal esterification or transesterification procedures and their chemical and spectral properties have been determined.
13 citations
Patent•
16 Apr 1976
TL;DR: In this paper, a base-catalysed transesterification of sucrose with a fatty acid ester is performed by a process comprising the steps of acidifying an aqueous dispersion of the material to between pH 4 and 7 to give an organic phase; at or above the melt temperature of the organic phase, recovering the organic phases; and mixing the organic ones with ethyl acetate containing 0 to 4% water, to give at a temperature of 0 to 20°C a liquid phase and a solid phase.
Abstract: Sucrose ester-containing material obtained by base-catalysed transesterification of sucrose with a fatty acid ester is purified by a process comprises the steps of:
(i) acidifying an aqueous dispersion of the material to between pH 4 and 7 to give an aqueous phase and an organic phase; (ii) at or above the melt temperature of the organic phase, recovering the organic phase; (iii) mixing the organic phase with ethyl acetate containing 0 to 4% water, to give at a temperature of 0 to 20°C a liquid phase and a solid phase; and (iv) recovering the solid phase as a sucrose ester-rich product.
13 citations
TL;DR: Phenyl groups are readily replaced in phosphate triesters by alcohols in general in the presence of casesium fluoride as discussed by the authors, in which casesium fluoride is used as an additive.
Abstract: Phenyl groups are readily replaced in phosphate triesters by alcohols in general in the presence of casesium fluoride.
12 citations
Patent•
26 Mar 1976
TL;DR: In this paper, high molecular weight, colorless polyesters suitable for shaping into filaments and films are obtained using novel catalysts selected from the group consisting of reaction products of specified antimony or zirconium (IV) compounds with (1) a carboxylate of calcium, manganese or zinc and (2) an acid anhydride, alcohol or glycol.
Abstract: High molecular weight, colorless polyesters suitable for shaping into filaments and films are obtained using novel catalysts selected from the group consisting of reaction products of specified antimony or zirconium (IV) compounds with (1) a carboxylate of calcium, manganese or zinc and (2) an acid anhydride, alcohol or glycol. The molar ratio of the antimony or zirconium compound to the aforementioned carboxylate is between 1:1 and 1:6. The catalysts are active in both transesterification and polycondensation. The rates of these reactions are more rapid than can be achieved using prior art catalysts.
11 citations
TL;DR: Tetrakis(dimethoxyboryl)silane has been synthesized from silicon tetrachloride, lithium, and dimethoxyboron chloride, and the boron-silicon bonds have been found highly susceptible to oxidative or hydrolytic cleavage, yet sufficiently stable to survive transesterification of boronic ester with ethylene glycol.
Abstract: Tetrakis(dimethoxyboryl)silane has been synthesized from silicon tetrachloride, lithium, and dimethoxyboron chloride, and the boron-silicon bonds have been found highly susceptible to oxidative or hydrolytic cleavage, yet sufficiently stable to survive transesterification of the boronic ester with ethylene glycol.
11 citations
Patent•
03 Jun 1976
TL;DR: Glycidyl methacrylate is produced by transesterifying methyl methacelate with glycidol in the presence of a polymerization inhibitor and a transesterification catalyst in which the catalyst is a salt of formula MeX where Me is an alkali metal ion and X is a cyanide, cyanate or thiocyanate ion.
Abstract: Glycidyl methacrylate is produced by transesterifying methyl methacrylate with glycidol in the presence of a polymerization inhibitor and a transesterification catalyst in which the catalyst is a salt of formula MeX where Me is an alkali metal ion and X is a cyanide, cyanate or thiocyanate ion.
Patent•
09 Aug 1976
TL;DR: In this paper, a crude methyl benzoate containing at least 80 wt.% methylbenzoate, which is a byproduct of production of dimethylterephthalate by catalytic oxidation of p-xylene and/or methyl-p-toluate and esterification of the resulting acids with methanol, is contacted with dipropylene glycol commercial isomer mixture in the presence of a catalyst for a transesterification to produce said benzosate.
Abstract: Process for production of dipropyleneglycol dibenzoate isomer mixture of the formulas: ##STR1## A crude methyl benzoate containing at least 80 wt.% methylbenzoate, which is a by-product of production of dimethylterephthalate by catalytic oxidation of p-xylene and/or methyl-p-toluate and esterification of the resulting acids with methanol, is contacted with dipropylene glycol commercial isomer mixture in the presence of a catalyst for a transesterification to produce said benzoate. The catalyst is an aluminum alkoxide or an aluminum silicon alkoxide containing the group Al O Si. The product is obtained in good yield, has good color, and is useful as a plasticizer for PVC.
TL;DR: The second-order rate constant for imidazole general base catalysis is decreased in D2O as compared with H2O by a factor of 3 as discussed by the authors, within error of unity.
TL;DR: Two models assumed for the kinetics of the transesterification of dimethyl terephthalate with ethylene glycol adequately describe the kinetic system and the first is more comprehensive and perhaps more realistic than the second.
Abstract: The present work shows that two models assumed for the kinetics of the transesterification of dimethyl terephthalate (DMT) with ethylene glycol adequately describe the kinetics of this system. The models were derived by considering only monomer ester intercharge reactions and were tested using methanol data from the literature. One model was obtained from a series-parallel reaction system while the other from an assumed reaction between a methyl ester group with ethyiene glycol. The two models are equally good up to 88% conversion of methyl ester groups but the first is more comprehensive and perhaps more realistic than the second.
TL;DR: In this article, the significance of oligomerization reactions was deduced by carrying out an analysis of the kinetics of possible ester interchange and transesterification reactions by use of data on methanol reported in the reviewed literature.
Abstract: Experimental investigations dealing with and mathematical models proposed for the kinetics of the transesterification of dimethyl terephthalate with ethylene glycol were critically reviewed. The models were found to be inadequate, while the investigations were found to be entirely lacking in information about the significance of oligomerization reactions. The significance of these reactions was deduced to be negligible by carrying out an analysis of the kinetics of possible ester interchange and transesterification reactions by use of data on methanol reported in the reviewed literature. This analysis was made possible by the application of numerical quadrature routines in testing the assumed models by the integral method.
Patent•
19 Jan 1976TL;DR: 1,4-Butanediol and a dialkyl benzenedicarboxylate such as dimethyl terephthalate are subjected to transesterification conditions and thereafter to polycondensation in the presence of a tetraalkyl titanate catalyst at a temperature within the range of 225° to 248° C as discussed by the authors.
Abstract: 1,4-Butanediol and a dialkyl benzenedicarboxylate such as dimethyl terephthalate are subjected to transesterification conditions and thereafter to polycondensation in the presence of a tetraalkyl titanate catalyst at a temperature within the range of 225° to 248° C.
Patent•
01 Dec 1976
TL;DR: Compositions of vanadyl alcoholate, organic titanate and polyhydric alcohol compounds are effective esterification and transesterification catalysts as discussed by the authors, however, they are not suitable for use as catalysts.
Abstract: Compositions of vanadyl alcoholate, organic titanate and polyhydric alcohol compounds are effective esterification and transesterification catalysts.
Patent•
16 Dec 1976
TL;DR: Alkayl acyloxystearates of formula CH3.(CH2)n. are prepd. by transesterification of a triglyceride of formula (II) with an alcohol ROH and acylation of the prod. as mentioned in this paper.
Abstract: Alkayl acyloxystearates of formula CH3.(CH2)n.CHO(O-COR1) -(CH2)15n COOR (I) (where R is 6-15C alkyl; R1 is 1-3C alkyl; n is 5-8) are prepd. by transesterification of a triglyceride of formula (II) with an alcohol ROH and acylation of the prod. using an acid anhydride of formula R1-CO-O-CO-R1. Used as solvents and protecting agents for antibiotics, vitamins etc. They are also useful in dermatology to replace perhydrosqualene oils. A typical prod. is 2'-ethyl hexyl 12-acetoxy stearate, prepd. by transesterifying hydrogenated castor oil with 2-ethyl hexanol using stearyl titanate as catalyst.
Patent•
08 Jan 1976TL;DR: In this article, a novel glycol and silicate-based surfactant composition is prepared by obtaining a silicatebased component by a selective process involving reaction of silicon tetrahalide with water and alcohol followed by transesterification with a polyether alcohol, and subsequently combining the silicate based component with glycols and/or polyglycol ethers.
Abstract: A novel glycol and silicate-based surfactant composition is prepared by (a) obtaining a silicate-based component by a selective process involving (i) reaction of silicon tetrahalide with water and alcohol followed by (ii) transesterification with a polyether alcohol, and (b) subsequently combining the silicate-based component with glycols and/or polyglycol ethers. The resulting surfactant composition is utilized as a stabilizer in the production of polyurethane foam.
Patent•
09 Dec 1976
TL;DR: In this article, high mwt polyesters suitable for injection molding are prepd by condensing butanediol-(1,4) optmixed with =10 mole % of another diol with dialkyl esters of tereand/or iso-phthalic acids.
Abstract: High mwt polyesters suitable for injection moulding are prepd by condensing butanediol-(1,4) optmixed with =10 mole % of another diol with dialkyl esters of tereand/or iso-phthalic acids opt mixed with is not >10 moles % other dialkyl esters of dicarboxylic acid, the transesterification being effected under pressure as an improvement Pref the stage comprises (1) transesterifying 1 mole of the ester with 105-19 mole diol using 001-04% catalyst (based on ester) under 2-10 bars at 180-230 degrees C, (2) polycondensing the prodt from (1) at 230-300 degrees C under 01-5 mmHg pressure in the molten state, and (3) further condensing the polyester from (2) under reduced pressure or inert atm at 5-50 degrees C lower than the polyester mpt until an intrinsic viscosity of 06-19dl/g is reached Formation of tetrahydrofuran in the transesterification stage is considerably reduced, amt of oligo-esters is reduced and the polyesters have higher mwt
Patent•
27 Jul 1976
TL;DR: In this article, the 4,4'-bis-(halogenmethyl)-ar-octahalogendiphenylethers with at least 2 moles of alkali acetate or formiate in the presence of alcohol as transesterification agent and solvent are used as intermediates for the production of insecticides, herbicides or hydrophobizing agents.
Abstract: Compounds of the formula: ##STR1## The compounds can be produced by reacting the corresponding 4,4'-bis-(halogenmethyl)-ar-octahalogendiphenylethers with at least 2 moles of alkali acetate or formiate in the presence of alcohol as transesterification agent and solvent. The compounds are useful as intermediates for the production of insecticides, herbicides or hydrophobizing agents.
TL;DR: In this article, a quantitative NMR analytical method has been developed for the transesterification and alcoholysis products using lanthanide displacement reagents and UMR, and the equilibrium constants of the above reactions during the synthesis of the polyester plasticizers based on adipic acid and various glycols have been calculated.
Abstract: A quantitative NMR analytical method has been developed for the transesterification and alcoholysis products using lanthanide displacement reagents and UMR. The equilibrium constants of the above reactions during the synthesis of the polyester plasticizers based on adipic acid and various glycols have been calculated. The glycols used were ethylene glycol (EG), propylene glycol (PG), and neopentyl glycol (NPG). The adipic acid-glycol bond resistance to alcoholysis has been found to decrease along the sequence NPG-EG-PG.
Patent•
06 Jul 1976
TL;DR: In this paper, an improved method for the transesterification of secondary alcohol borate esters with methanol was proposed, the improvement comprising separating a portion of the extractive distillation column overhead as a reflux stream and returning said refluxstream to the extractively distilled column.
Abstract: An improved method for the transesterification of secondary alcohol borate esters with methanol, the improvement comprising separating a portion of the extractive distillation column overhead as a reflux stream and returning said reflux stream to the extractive distillation column between points located at or below the point at which the borate ester feed is introduced to the column and at or above the point at which methanol is introduced to the column, thus reducing the amount of boron-containing compounds in the crude secondary alcohol product stream.
Patent•
06 May 1976
TL;DR: In this article, animal fats are converted to plastic edible fats by mixing 1 pt. of the molten (I) with 0.4-9 pts. of a lightly unsatd. vegetable oil and hydrogenating the mixt.
Abstract: Animal fats (I) are converted to plastic edible fats by mixing 1 pt. of the molten (I) with 0.4-9 pts. of a lightly unsatd. vegetable oil and hydrogenating the mixt. at 180-220 degrees C using an H2 excess press. of =2 Kp/cm2 and an Ni catalyst whole activity is =35 degrees C so that the polyunsatd. fatty acids of (I) and (II) are selectively hydrogenated and a partial transesterification of (I) with (II) occurs. The process enables a prod. having an m. pt. of i9-40 degrees C and a hardness of 130-140 g/cm to be produced which are free from the characteristic smell and taste of (I) and which is stable during further processing esp. to margarine. Pre-determination of end-prod. props. possible. No pre-refining of (I) reqd.
TL;DR: In this article, eight cyclic phosphonates and thiophosphonates of the type have been synthesized by the Arbuzov rearrangement or by normal esterification or transesterification procedures and their chemical and spectral properties have been determined.
Abstract: Eighteen cyclic phosphonates and thiophosphonates of the type have been synthesized by the Arbuzov rearrangement or by normal esterification or transesterification procedures and their chemical and spectral properties have been determined.
TL;DR: Phenyl groups are readily replaced in phosphate triesters by alcohols in general in the presence of casesium fluoride as mentioned in this paper, in which casesium fluoride is used as an additive.
Abstract: Phenyl groups are readily replaced in phosphate triesters by alcohols in general in the presence of casesium fluoride.
TL;DR: Tetrakis(dimethoxyboryl)silane has been synthesized from silicon tetrachloride, lithium, and dimethoxyboron chloride, and the boron-silicon bonds have been found highly susceptible to oxidative or hydrolytic cleavage, yet sufficiently stable to survive transesterification of boronic ester with ethylene glycol as mentioned in this paper.
Abstract: Tetrakis(dimethoxyboryl)silane has been synthesized from silicon tetrachloride, lithium, and dimethoxyboron chloride, and the boron-silicon bonds have been found highly susceptible to oxidative or hydrolytic cleavage, yet sufficiently stable to survive transesterification of the boronic ester with ethylene glycol.
Patent•
28 Oct 1976
TL;DR: Olefins may be esterified by reaction with esters of saturated alcohols containing at least two carbon atoms in the presence of a catalytic amount of a tin halide catalyst, the reaction being effected at temperatures ranging from about 0° to about 150° C as discussed by the authors.
Abstract: Olefins may be esterified by reaction with esters of saturated alcohols containing at least two carbon atoms in the presence of a catalytic amount of a tin halide catalyst, the reaction being effected at temperatures ranging from about 0° to about 150° C.