A type of easy-to-dye porous modified polyester fibers and preparing method thereof are disclosed. The preparing method is using the modified polyester melt through a porous spinneret with FDY process; wherein the modified polyester is a product of an esterification and successive polycondensation reactions of an evenly mixed terephthalic acid, ethylene glycol, main chain silicated diol, 2,2,3,4,5,5-hexamethyl-3,4-hexanediol, and metal oxide doped Sb.sub.2O.sub.3 powder; wherein the main chain silicated diol is selected from the group consisting of dimethylsiloxane diol, dimethyldiphenyldisiloxane glycol and tetramethyldisiloxane diol. The structural formula of 2,2,3,4,5,5-hexamethyl-3,4-hexanediol is as follows: ##STR00001## The dye uptake and the K/S value of the prepared easy-to-dye porous modified polyester fiber are high. This invention features a method with ease of application and a product with good dyeing performance and good quality.

A polyethylene terephthalate (PET) polymer having diacid units derived from diacid compounds, said diacid units comprising: a) from 92.50 mol % to 97.75 mol % of terephthalic units derived from terephthalic acid (TA) or an ester thereof, and b) from 2.25 mol % to 7.50 mol % of 2,5-FDCA units derived from 2,5-furandicarboxylic acid (2,5-FDCA) or an ester thereof, and—diol units derived from diol compound(s), the diol units having monoethylene glycol units derived from monoethylene glycol (MEG), as well as to a method to prepare such a PET polymer. The use of a 2,5-FDCA compound selected from 2,5-furandicarboxylic acid (2,5-FDCA) and esters thereof as an anti-crystallization comonomer in a PET polymer and a bio-based PET polymer in which the anti-crystallisation comonomer is bio-based.

A polyethylene terephthalate (PET) polymer having diacid units derived from diacid compounds, said diacid units comprising: a) from 92.50 mol % to 97.75 mol % of terephthalic units derived from terephthalic acid (TA) or an ester thereof, and b) from 2.25 mol % to 7.50 mol % of 2,5-FDCA units derived from 2,5-furandicarboxylic acid (2,5-FDCA) or an ester thereof, and—diol units derived from diol compound(s), the diol units having monoethylene glycol units derived from monoethylene glycol (MEG), as well as to a method to prepare such a PET polymer. The use of a 2,5-FDCA compound selected from 2,5-furandicarboxylic acid (2,5-FDCA) and esters thereof as an anti-crystallization comonomer in a PET polymer and a bio-based PET polymer in which the anti-crystallisation comonomer is bio-based.

The present disclosure relates to a polyester copolymer having excellent strength and heat resistance, and a product comprising the same.

The present disclosure relates to a polyester copolymer having excellent strength and heat resistance, and a product comprising the same.

Provided are a polyester resin having high heat resistance and degree of crystallinity, a preparation method thereof, and a resin molded article formed therefrom, the resin molded article having superior heat resistance and mechanical strength and maintaining high transparency.

The invention provides a polycondensation catalyst for producing polyester by an esterification reaction or a transesterification reaction of a dicarboxylic acid or an ester-forming derivative thereof and a glycol, wherein the polycondensation catalyst comprises particles of a water-insoluble or hardly water-soluble phosphate having on the surfaces a coating layer of titanic acid in an amount, of 0.1 to 100 parts by weight in terms of TiO.sub.2 per 100 parts by weight of the phosphate.

A process for making a high molecular weight poly(hydroxy acid) polymer having good thermal stability and a weight average molecular weight of >100,000 by GPC. The process includes mixing glycolic acid and/or lactic acid, and a diol or di-acid initiator, and at least one multifunctional initiator to form a liquid monomer mixture in an agitated polycondensation reactor. Polycondensing to form a liquid reaction mixture comprising a pre-polymer having a weight average molecular weight of >10,000 by GPC, and greater than 80% by mole hydroxyl or carboxyl end-group termination, then crystallizing to form a first solid reaction mixture. Then solid state polycondensing the solid reaction mixture to form a solid reaction mixture having a moisture level less than 50 ppm by weight. Then mixing the solid reaction mixture with an appropriate reactive coupling agent in a melting and mixing extruder to couple and form the reaction mixture and form the poly(hydroxy acid) polymer.

A process for making a high molecular weight poly(hydroxy acid) polymer having good thermal stability and a weight average molecular weight of >100,000 by GPC. The process includes mixing glycolic acid and/or lactic acid, and a diol or di-acid initiator, and at least one multifunctional initiator to form a liquid monomer mixture in an agitated polycondensation reactor. Polycondensing to form a liquid reaction mixture comprising a pre-polymer having a weight average molecular weight of >10,000 by GPC, and greater than 80% by mole hydroxyl or carboxyl end-group termination, then crystallizing to form a first solid reaction mixture. Then solid state polycondensing the solid reaction mixture to form a solid reaction mixture having a moisture level less than 50 ppm by weight. Then mixing the solid reaction mixture with an appropriate reactive coupling agent in a melting and mixing extruder to couple and form the reaction mixture and form the poly(hydroxy acid) polymer.

An integrated process is useful for producing 2,5-furandicarboxylic acid (FDCA) and/or a derivative thereof from a six-carbon sugar-containing feed. The process includes a) dehydrating a feed containing a six-carbon sugar unit, in the presence of a bromine source and of a solvent, to generate an oxidation feed that contains at least one of 5-hydroxymethylfurfural (HMF) and/or a derivative or derivatives of HMF in the solvent, together with at least one bromine containing species; b) contacting the oxidation feed from step (a) with a metal catalyst and with an oxygen source under oxidation conditions to produce an oxidation product mixture of at least FDCA and/or a derivative thereof, the solvent, and a residual catalyst; c) purifying and separating the mixture obtained in step (b) to obtain FDCA and/or a derivative thereof and the solvent; and d) recycling at least a portion of the solvent obtained in step (c) to step (a).