Semicrystalline bifuran polyesters wherein the diacid and/or diol components include bifuran units such as those derived from 2,2′-bifuran-5,5′-dicarboxylic acid (BFA), dimethyl-2,2′-bifuran-5,5′-dicarboxylate (BFE), and/or bis(hydroxyethyl) bifuranoate (BHEB) Polyethylene-BFE (PEBF) having a high ΔH.sub.f and high T.sub.g determined by DSC on the second heating ramp is described. Polybutylene-BFE (PBBF), polyhexylene-BFE (PHBF), polypropylene-BFE (PPBF), etc., are also described. Method for making bifuran polyesters includes melt esterification or transesterification and polycondensation of one or more monomers comprising a diacid component and a diol component, wherein the one or more monomers include a bifuran monomer, such as BFA, BFE, BHEB or BFD. Also described is a method of forming a bifuran polyester prepolymer in the melt, pelletization, crystallization, and solid state polymerization.

Some variations provide an oligomer composition comprising: polarizable first thermotropic liquid-crystal oligomer molecules (preferably urethanes or ureas) containing first triggerable reactive end groups, wherein the first triggerable reactive end groups are selected from the group consisting of hydroxyl, isocyanate, blocked isocyanate, acrylate, epoxide, amine, vinyl, ester, thiol, conjugated diene, substituted alkene, furan, maleimide, anthracene, and combinations thereof, and wherein the polarizable first thermotropic liquid-crystal oligomer molecules are characterized by a weight-average molecular weight from about 200 g/mol to about 10,000 g/mol; optionally, a plurality of polarizable second thermotropic liquid-crystal oligomer molecules containing second triggerable reactive end groups, wherein the second triggerable reactive end groups are capable of reacting with the first triggerable reactive end groups; and optionally, a reactive coupling agent capable of reacting with the first triggerable reactive end groups. Methods are described for converting the oligomer composition into an anisotropic thermally conductive polymer. Many commercial uses are disclosed.

Some variations provide an oligomer composition comprising: polarizable first thermotropic liquid-crystal oligomer molecules (preferably urethanes or ureas) containing first triggerable reactive end groups, wherein the first triggerable reactive end groups are selected from the group consisting of hydroxyl, isocyanate, blocked isocyanate, acrylate, epoxide, amine, vinyl, ester, thiol, conjugated diene, substituted alkene, furan, maleimide, anthracene, and combinations thereof, and wherein the polarizable first thermotropic liquid-crystal oligomer molecules are characterized by a weight-average molecular weight from about 200 g/mol to about 10,000 g/mol; optionally, a plurality of polarizable second thermotropic liquid-crystal oligomer molecules containing second triggerable reactive end groups, wherein the second triggerable reactive end groups are capable of reacting with the first triggerable reactive end groups; and optionally, a reactive coupling agent capable of reacting with the first triggerable reactive end groups. Methods are described for converting the oligomer composition into an anisotropic thermally conductive polymer. Many commercial uses are disclosed.

A bio-based polycarbonate ester resin is environment friendly by not containing a bisphenol, and exhibits excellent heat resistance, transparency, strength, hardness, dimensional stability and chemical resistance. Thus, the bio-based polycarbonate ester resin is suitable for use in an eyeglass frame. In addition, various colors may be painted and coated on during post-processing, a separate additive is not required during a molding process, and processing is undergone at a temperature lower than that for conventional plastic materials for an eyeglass frame, and thus manufacturing costs may be reduced.

A bio-based polycarbonate ester resin is environment friendly by not containing a bisphenol, and exhibits excellent heat resistance, transparency, strength, hardness, dimensional stability and chemical resistance. Thus, the bio-based polycarbonate ester resin is suitable for use in an eyeglass frame. In addition, various colors may be painted and coated on during post-processing, a separate additive is not required during a molding process, and processing is undergone at a temperature lower than that for conventional plastic materials for an eyeglass frame, and thus manufacturing costs may be reduced.

A polyester resin composition comprising a crystalline wholly aromatic polyester which is a polycondensate of an aromatic dicarboxylic acid and an aromatic diol, and a filler, wherein a structural unit derived from the aromatic dicarboxylic acid comprises a structural unit represented by chemical formula (1): ##STR00001## and a structural unit derived from the aromatic diol comprises chemical formula (4): ##STR00002##
wherein content of a residue of 4,4′-dicarboxy diphenyl ether (corresponding to the structural units represented by chemical formula (1)) and a residue of 4,4′-dihydroxy benzophenone (corresponding to the structural units represented by chemical formula (4)) is at least 80 mol % in the entire structural units of the crystalline wholly aromatic polyester.

A polyester resin composition comprising a crystalline wholly aromatic polyester which is a polycondensate of an aromatic dicarboxylic acid and an aromatic diol, and a filler, wherein a structural unit derived from the aromatic dicarboxylic acid comprises a structural unit represented by chemical formula (1): ##STR00001## and a structural unit derived from the aromatic diol comprises chemical formula (4): ##STR00002##
wherein content of a residue of 4,4′-dicarboxy diphenyl ether (corresponding to the structural units represented by chemical formula (1)) and a residue of 4,4′-dihydroxy benzophenone (corresponding to the structural units represented by chemical formula (4)) is at least 80 mol % in the entire structural units of the crystalline wholly aromatic polyester.

Fiber-reinforced terephthalate-co-4,4′-bibenzoate copolyester behaves like a liquid crystalline polymer, providing fast crystallization, short cycling times, high T.sub.g and T.sub.m, high strength and stiffness, while the viscosity is unexpectedly reduced at a low fiber loading ratio. In an injection molding process, the viscosity of the fiber reinforced copolyester at low fiber loading is reduced by increasing the fiber loading.

Fiber-reinforced terephthalate-co-4,4′-bibenzoate copolyester behaves like a liquid crystalline polymer, providing fast crystallization, short cycling times, high T.sub.g and T.sub.m, high strength and stiffness, while the viscosity is unexpectedly reduced at a low fiber loading ratio. In an injection molding process, the viscosity of the fiber reinforced copolyester at low fiber loading is reduced by increasing the fiber loading.

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.