Showing papers on "Transesterification published in 1983"

Conversion of used frying oil to diesel fuel by transesterification: preliminary tests

Abstract: Used frying oil was transesterified by reaction with excess alcohol under both acidic and basic conditions. The alcohols used were: methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-ethoxyethanol. Yields of the fuels determined by gas chromatography and their viscosities are reported. The best result was obtained using methanol with catalysis by potassium hydroxide. The methyl ethyl and 1-butyl esters all ran very well in short-term engine tests with a laboratory high-speed diesel engine.

Synthesis of higher polyol fatty acid polyesters using carbonate catalysts

Abstract: An improved solvent-free transesterification process for producing polyol fatty acid polyesters is disclosed. In this process, a mixture of a polyol, a fatty acid methyl, 2-methoxy ethyl or benzyl ester, an alkali metal fatty acid soap, and potassium carbonate, sodium carbonate or barium carbonate as a catalyst is heated to form a homogeneous melt. To this melt is subsequently added excess fatty acid methyl, 2-methoxy ethyl or benzyl ester, yielding the desired polyol fatty acid polyesters.

Blends of poly(butylene terephthalate) and a polyarylate before and after transesterification

Abstract: Blends of poly(butylene terephthalate) (PBT) and a copolyester of bisphenol-A with 50% terephthalate-50% isophthalate (PAr), before and after transesterification, have been studied by thermal and dynamic mechanical tests to determine crystallinity and phase behavior. Blends without transesterification, as prepared by solution precipitation, show a single Tg, indicating amorphous miscibility of PBT and PAr. A melting-point depression for PBT crystals is not observed; this means that PBT crystallizes excluding PAr and the entropy of melting is small. The highest fractional crystallinity for PBT is obtained at 20-35% of PAr. Transesterified blends were obtained by holding the physical blends at 250°C for up to 16 h. The transesterified systems show higher Tg's than the corresponding physical blends and also show a marked melting-point depression and lesser PBT crystallinity at the corresponding increased PAr content.

Semi or fully continuous process for polyester of bisphenol and dicarboxylic acid by transesterification polymerization and product thereof

Abstract: Linear aromatic polyesters of bisphenols and dicarboxylic compounds are prepared by transesterification polymerization in either a fully continuous process or in a semi-continuous process wherein a first stage is conducted batchwise and a second stage is conducted in a continuous manner wherein the second stage employs a wiped film reactor, alternatively, a wiped film reactor followed by a vented extrusion reactor. The processes are preferably conducted in the presence of a catalyst in liquid form, and further under conditions wherein the catalyst is introduced to the polymerization concurrent with the introduction of liquid phase reactants to avoid substantial heating of the reactants in contact with the catalyst prior to onset of the transesterification reaction. The products of the processes have an unexpectedly low polydispersity.

Transesterification of esters

Abstract: A process for the transesterification of a carboxylic or carbonic acid ester comprises reacting the carboxylic or carbonic acid ester under transesterification conditions with an alcohol in the presence, as catalyst, of either (i) a Group V element-containing Lewis base and an epoxide or (ii) a cyclic amidine. The Lewis base can be an organic compound containing trivalent phosphorus or nitrogen and can be an amine, for example an amidine. The process can be operated in the liquid phase at a temperature of from 15° to 150° C., and the catalyst is employed in solution. Preferred catalysts are those where the cyclic amidine forms part of a fused ring system containing six and five membered rings, six and seven membered rings or two six membered rings.

Process for the manufacture of a methyl, ethyl, propyl or butyl ester of a fatty acid suitable for use as diesel fuel

Abstract: A fatty acid ester usable as diesel fuel is prepared. The process of preparation according to the invention comprises an operation of transesterification of an oil or of a vegetable or animal fat by means of an aliphatic C1-C4 alcohol with separation of the glycerine formed up to a degree of conversion of at least 95 %, followed by a treatment over activated earth. The product obtained has a Conradson residue value on "10% residue" lower than 0.5 % which makes it suitable for use in all diesel engines.

Titanium catalyzed transesterification

Abstract: Ether cleavage in transesterifications of pyridyloxyphenoxy alkanoic acid compounds is reduced by employing titanium compounds as catalysts.

Process for manufacture of fatty acid esters of hydroxy sulfonates

Abstract: A method is disclosed for preparing fatty acid isethionate soaps through direct esterification wherein the catalyst is quenched by an alkaline compound at the end of the esterification. Quenching inhibits transesterification between isethionate and later added stearic acids. Transesterification is undesirable impairing lather and bar soap firmness. The traditional stripping of lower molecular weight fatty acids is no longer necessary where low ratios of fatty acids to isethionates are utilized. Alternatively, stripping can be avoided with traditional molar ratios provided water co-distillate fatty acid is not recycled. Finally, it has been shown that zinc catalyzed reactions provide optimum yield and low corrosion at pH about 2.0 to 2.5.

Process for the production of dianhydrohexitol mixtures and liquid mixture of dianhydrohexitols

Abstract: Liquid dianhydrohexitol mixtures are prepared from diacylation products of hexitols and compounds such as organic carboxylic acids, carboxylic acid anhydrides, carboxylic acid halides, ketene and carbonic acid ester derivatives. More specifically, such diacylation products are simultaneously dehydrated and isomerized by subjecting them to a temperature of at least 130° C. in the presence of a strong acid to yield diacylated dianhydrohexitol isomer mixtures. These isomer mixtures are then converted to dianhydrohexitol isomer mixtures by hydrolysis or transesterification. Suitable strong acids include proton acids, Lewis acids and heterogeneous acid catalysts (e.g., ion exchange resins). The mixtures of the present invention are characterized by a minimal tendency towards crystallization. These mixtures are particularly useful as chain extending agents in the production of polyurethanes.

Gas-liquid phase-transfer catalysis: catalytic and continuous transesterification reaction

Abstract: Transesterification d'acetates d'ethyle ou de pentyle et de benzoate de methyle par reaction avec des alcanols en presence de 18-crown-6 ou de carbowax 6000

Boron- and nitrogen-containing compositions and their use in polycarbonate and polyester-polycarbonate synthesis

Abstract: Boron- and nitrogen-containing compositions prepared by the reaction of a quaternary ammonium hydroxide with a trialkyl or triaryl borate are useful for the preparation of the active catalyst species in the transesterification of reaction for the production of polycarbonates or polyester-polycarbonates from diaryl carbonates (optionally in admixture with diaryl dicarboxylates) and dihydroxyaromatic compounds.

Low smoke, halohydrocarbon-compatible urethane-isocyanurate foam compositions

Abstract: Compositions having improved compatibility of halohydrocarbon blowing agents such as trichlorofluoromethane and suitable for curing with polyisocyanates to give low smoke urethane isocyanate foams are described. The compositions include the transesterification products of the residue obtained from the manufacture of dimethyl terephthalate and ethylene glycol or a polyethylene glycol; the transesterification product of that residue and a higher alkylene glycol or higher polyalkylene glycol; and a polyether polyol having an average hydroxyl functionality of at least 4.

Preparation of branched polycarbonates by transesterification with a triaryl tricarboxylic acid branching agent

Abstract: This invention relates to branched polycarbonates that are made by transesterification having a triaryl tricarboxylic acid as a branching agent.

Polyisocyanurate foam and reaction mixture for making same

Abstract: Polyisocyanurate foam in which the polyol content is largely a polyol mixture prepared by the transesterification wtih a glycol of a residue obtained from the manufacture of dimethyl terephthalate and in which the foam has been prepared using fluorocarbon blowing agent and amide diol to improve compatibility between the polyol and the blowing agent.

A process for converting olefins to carboxylic acids or esters using soluble iridium compounds

Abstract: OF THE DISCLOSURE A homogeneous process for converting olefins to carboxylic acids and/or esters. The process com-prises contacting an olefin and a formate ester or transesterification product thereof with a soluble iridium catalyst and iodide promoter at temperatures of from 150 to 300°C in a carboxylic acid solvent.

Transesterification of mixtures of triglycerides in the presence of cotton-plant lipase

Abstract: The transesterification of mixtures of cottonseed oil with beef fat in the presence of cotton plant lipase immobilized on a solid support has been studied. A regime for the transesterification of the triglycerides permitting transesterificates suitable for the production of margarine and bakers' and confectioners' articles have been found.

Synthesis, characterization, and kinetics of thermal degradation of copolyesters†

Abstract: Random terephthalate copolyesters of ethylene glycol and propylene glycol (1,2-propanediol) with various contents of monomeric units of the diols were prepared by transesterification. The actual content of each monomeric unit in the copolyester was determined by 1H NMR. The thermal behaviour of the copolyesters was studied by differential thermal analysis. Kinetic order, heat and entropy of fusion, and activation energy for the thermal degradation of the copolyesters, were obtained.

Ketocarboxylic acid esters and their use in cosmetics

Abstract: Suitable oil or fat components for cosmetic and pharmaceutical preparations are novel 3-oxocarboxylic acid esters of the general formula R-CH2-CO-CHR-CO2-R', in which R represents alkyl or alkenyl radicals having 4-16 C atoms and R' represents alkyl or alkenyl radicals having 8-28 C atoms Particularly useful compounds are those esters which have been prepared from fatty alcohol mixtures, and those which contain at least 25 mol % of C = C double bonds in R and/or R' They are prepared by transesterification of a corresponding condensation product of 2 mol of fatty acid methyl ester with long-chain primary alcohols, preferably alcohol mixtures, without the use of a solvent

Production of polyester

Abstract: PURPOSE:To obtain a polyester having good color and excellent heat stability, by transesterifying a lower-alkyl terephthalate with a glycol ester without forced agitation, and then polycondensing the reaction mixture. CONSTITUTION:In producing a polyester by transesterifying a lower alkyl ester of a terephthalic acid-based dicarboxylic acid (dimethyl terephthalate) with at least one glycol (e.g., ethylene glycol) in the presence of a transesterification catalyst (e.g., manganese acetate) and polycondensing the transesterification product; at least part of said transesterification is carried out without forced agitation. It is possible to facilitate the production of a polyester having good color, a low content of terminal carboxyl groups and so excellent heat stability.

Production of high-molecular compound

Abstract: PURPOSE:To produce a solvent-soluble and moldable high-MW compound, by esterifying or transesterifying a polyhydroxyl compound by using a polycarboxylic acid as a crosslinking agent. CONSTITUTION:In producing a high-MW compound by addition-polymerizing an organic compound having at least three active hydrogens atoms (e.g., glycerol) with an ethylene oxide-containing alkylene oxide to obtain a polyhydroxyl compound, average MW >=10,000, and crosslinking the polyhydroxyl compound; a solvent-soluble and moldable high-MW compound, average MW >=20,000, is produced by carrying out the esterification or transesterification by using a polycarboxylic acid, its anhydride or its lower alkyl ester (e.g., malonic acid, its monomethyl ester or its anhydride) as a crosslinking agent.

Production of aromatic polyester

Abstract: PURPOSE:To produce an aromatic polyester of excellent quality in good production efficiency without fear of equipment corrosion, by employing conventional polyester polymerization equipment as such and using inexpensive, readily available starting materials. CONSTITUTION:In the first stage, an aromatic dicarboxylic acid alkyl ester is transesterified with an at least equivalent amount of a carboxylic acid aryl ester in the presence of a transesterification catalyst (e.g., a compound containing tin or lead) while the formed aliphatic alkyl ester is being distilled off. In the second stage, an acyl derivative of an aromatic dihydroxy compound is added to the produced aromatic dicarboxylic acid diaryl ester containing unreacted aliphatic carboxylic acid aryl ester, and the mixture is subjected to a polycondensation reaction. The aliphatic carboxylic acid aryl ester distilled off during the polycondensation reaction is recycled as a reaction material for the first stage. In this way, the titled polyester is obtained.