Processes are described for purifying a biphenyldicarboxylic acid product containing one or more impurities, particularly at least formylbiphenylcarboxylic acid. In the processes, a mixture comprising the biphenyldicarboxylic acid product is contacted with hydrogen in the presence of a hydrogenation catalyst under conditions to selectively reduce at least part of the formylbiphenylcarboxylic acid to produce a hydrogenation effluent comprising (i) hydroxymethylbiphenylcarboxylic acid and/or methylbiphenylcarboxylic acid, and (ii) biphenylcarboxylic acid. At least a portion of the biphenyldicarboxylic acid is then separated from the hydrogenation effluent. Advantageously, a polyester product may be produced from the separated biphenyldicarboxylic acid.

A process for oxidizing methyl-substituted biphenyl compounds comprises contacting a mixture comprising isomers of at least one methyl-substituted biphenyl compound with a source of oxygen, wherein the mixture comprises at least 20 wt % of isomer(s) having a methyl group at a 2-position or a 3-position on at least one benzene ring and at least 50 wt % of isomer(s) having a methyl group at a 4-position on at least one benzene ring, wherein said percentages are based on the total weight of the at least one methylbiphenyl compound in the mixture.

A process for oxidizing methyl-substituted biphenyl compounds comprises contacting a mixture comprising isomers of at least one methyl-substituted biphenyl compound with a source of oxygen, wherein the mixture comprises at least 20 wt % of isomer(s) having a methyl group at a 2-position or a 3-position on at least one benzene ring and at least 50 wt % of isomer(s) having a methyl group at a 4-position on at least one benzene ring, wherein said percentages are based on the total weight of the at least one methylbiphenyl compound in the mixture.

The method according to this disclosure is a method for separating an unsaturated hydrocarbon having 2 or 3 carbon atoms and a halogenated unsaturated carbon compound formed by replacing at least one of hydrogen atoms included in the unsaturated hydrocarbon with a fluorine atom, from each other and is a method for selectively adsorbing either the unsaturated hydrocarbon or the halogenated unsaturated carbon compound by a porous coordination polymer that includes a metallic ion having a valence of 2 to 4 and an aromatic anion having 1 to 6 aromatic ring(s).

The method according to this disclosure is a method for separating an unsaturated hydrocarbon having 2 or 3 carbon atoms and a halogenated unsaturated carbon compound formed by replacing at least one of hydrogen atoms included in the unsaturated hydrocarbon with a fluorine atom, from each other and is a method for selectively adsorbing either the unsaturated hydrocarbon or the halogenated unsaturated carbon compound by a porous coordination polymer that includes a metallic ion having a valence of 2 to 4 and an aromatic anion having 1 to 6 aromatic ring(s).

This disclosure relates to methods for producing purified aromatic esters useful as plasticizers, to the purified aromatic esters, and to polymer compositions containing the purified esters. The purified aromatic esters can be produced by esterifying carboxylic acid with methyl or ethyl alcohol, separating the resulting methyl or ethyl esters from the carboxylic acid and any byproduct impurities, and then transesterifying the methyl or ethyl esters with C.sub.4 to C.sub.14 alcohol to produce the purified aromatic esters. Additionally, precipitation, filtration, and wash steps can be employed to purify the carboxylic acid, the methyl or ethyl alcohol, and/or the aromatic esters.

This disclosure relates to methods for producing purified aromatic esters useful as plasticizers, to the purified aromatic esters, and to polymer compositions containing the purified esters. The purified aromatic esters can be produced by esterifying carboxylic acid with methyl or ethyl alcohol, separating the resulting methyl or ethyl esters from the carboxylic acid and any byproduct impurities, and then transesterifying the methyl or ethyl esters with C.sub.4 to C.sub.14 alcohol to produce the purified aromatic esters. Additionally, precipitation, filtration, and wash steps can be employed to purify the carboxylic acid, the methyl or ethyl alcohol, and/or the aromatic esters.

A process for selective oxidation of dimethyl-1,1-biphenyl to form methyl-1,1-biphenyl mono-carboxylic acid(s), comprising contacting a solution of dimethyl-1,1-biphenyl in acetic acid solvent in the presence of a Co(II) acetate catalyst and air, and optionally adding a co-solvent, or adding sodium or potassium acetate, and oxidizing the dimethyl-1,1-biphenyl under time and temperature conditions sufficient to form one or more methyl-1,1-biphenyl mono-carboxylic acid(s). The mono-carboxylic acids are advantageously isolated and esterified to form biphenyl mono-esters for use as plasticizers.

A process for selective oxidation of dimethyl-1,1-biphenyl to form methyl-1,1-biphenyl mono-carboxylic acid(s), comprising contacting a solution of dimethyl-1,1-biphenyl in acetic acid solvent in the presence of a Co(II) acetate catalyst and air, and optionally adding a co-solvent, or adding sodium or potassium acetate, and oxidizing the dimethyl-1,1-biphenyl under time and temperature conditions sufficient to form one or more methyl-1,1-biphenyl mono-carboxylic acid(s). The mono-carboxylic acids are advantageously isolated and esterified to form biphenyl mono-esters for use as plasticizers.

A process for selective oxidation of dimethyl-1,1-biphenyl to form methyl-1,1-biphenyl mono-carboxylic acid(s), comprising contacting a solution of dimethyl-1,1-biphenyl in acetic acid solvent in the presence of a Co(II) acetate catalyst and air, and optionally adding a co-solvent, or adding sodium or potassium acetate, and oxidizing the dimethyl-1,1-biphenyl under time and temperature conditions sufficient to form one or more methyl-1,1-biphenyl mono-carboxylic acid(s). The mono-carboxylic acids are advantageously isolated and esterified to form biphenyl mono-esters for use as plasticizers.