A copolyester, comprising structural units represented by [I], [II], [III] and [IV]. The number of structural units represented by [III] is 1-99% of the number of structural units represented by [I], and the number of structural units represented by [IV] is 0-99% of the number of structural units represented by [I]. Also provided are a preparation method therefor and an application thereof. Because an introduced high-temperature self-crosslinking group and an ion group can improve the melt viscosity and the melt intensity during burning of a copolyester, and effectively enhance the char-forming capability of the copolyester, the copolyester exhibits excellent flame retardance and anti-dripping performance. The preparation process for the copolyester is mature, convenient to operate, and easy to control and apply to industrial production.

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A method for manufacture of polyesters with recycle content is described in various aspects. The methods of the present disclosure effectively and cost-efficiently incorporates recycled DMT into existing TPA-based polyester manufacturing systems. Recycle feed compositions for manufacture of polyesters with recycle content and recycled content polyesters are also described.

Disclosed herein are processes of making furan-based polyamides using solvent-free melt condensation of a diamine and an ester derivative of 2,5-furandicarboxylic acid with a C.sub.2 to C.sub.12 aliphatic diol or a polyol. The processes comprise a) forming a reaction mixture by mixing one or more diamines, a diester comprising an ester derivative of 2,5-furandicarboxylic acid with a C.sub.2 to C.sub.12 aliphatic diol or a polyol, and a catalyst, such that the diamine is present in an excess amount of at least 1 mol % with respect to the diester amount; and b) melt polycondensing the reaction mixture in the absence of a solvent at a temperature in the range of 60° C. to a maximum temperature of 250° C. under an inert atmosphere, while removing alkyl alcohol to form a furan-based polyamide, wherein the one or more diamines comprises an aliphatic diamine, an aromatic diamine, or an alkylaromatic diamine.

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A method for producing an oligomeric polyethylene terephthalate (PET) substrate for use in a recycled PET (rPET) manufacturing process comprises adding recycled bis-hydroxylethyleneterephthalate (rBHET) or a higher molecular weight oligomer derived from rBHET and water to a reaction zone and reacting the rBHET and water in the reaction zone to produce an oligomeric PET substrate represented by the Formula (I): wherein R1 is a carboxyl end group or a hydroxyl end group, R2 is a carboxyl end group or a hydroxyl end group, and n is a degree of polymerisation (Dp).

The present disclosure relates to a catalyst system to produce crystallizable polyester compositions which comprise residues of terephthalic acid, neopentyl glycol (NRG), 1,4-cyclohexanedimethanol (CHDM), ethylene glycol (EG), and diethylene glycol (DEG), in certain compositional ranges having certain advantages and improved properties including recyclability.

The present disclosure relates to a catalyst system to produce crystallizable polyester compositions which comprise residues of terephthalic acid, neopentyl glycol (NRG), 1,4-cyclohexanedimethanol (CHDM), ethylene glycol (EG), and diethylene glycol (DEG), in certain compositional ranges having certain advantages and improved properties including recyclability. The present disclosure also relates to a catalyst system to produce crystallizable polyester compositions which comprise residues of recycled terephthalic acid, recycled neopentyl glycol (NRG), recycled 1,4-cyclohexanedimethanol (CHDM), recycled ethylene glycol (EG), and/or recycled diethylene glycol (DEG), in certain compositional ranges having certain advantages and improved properties including recyclability.

The present disclosure relates to a catalyst system to produce crystallizable polyester compositions which comprise residues of terephthalic acid, neopentyl glycol (NRG), 1,4-cyclohexanedimethanol (CHDM), ethylene glycol (EG), and diethylene glycol (DEG), in certain compositional ranges having certain advantages and improved properties including recyclability. The present disclosure also relates to a catalyst system to produce crystallizable polyester compositions which comprise residues of recycled terephthalic acid, recycled neopentyl glycol (NRG), recycled 1,4-cyclohexanedimethanol (CHDM), recycled ethylene glycol (EG), and/or recycled diethylene glycol (DEG), in certain compositional ranges having certain advantages and improved properties including recyclability.

A method for improving L* color of polyethylene terephthalate polymer, the method including bis-hydroxylethyl-eneterephthalate being polycondensed to produce said polyethylene terephthalate polymer in a polyethylene terephthalate manufacturing process, and wherein said process requires an antimony-containing catalyst, the method comprising the steps of: i) adding said antimony-containing catalyst at a temperature in a range of a melting point of said BHET to an upper temperature of 220° C.; and ii) exposing said BHET in a molten state to glycol removal before addition of said antimony-containing catalyst.

Provided is a tape including a composition having a copolyester including polymeric units derived from ethylene glycol and terephthalic acid or a diester thereof and >0.50 and <5.00 wt % of polymeric units with regard to the total weight of the polyester derived from an oligomeric dihydroxy compound having a number average molecular weight of >500 g/mol and <5000 g/mol. Such tape has an improved tensile-impact strength and a reduced proneness to splitting during weaving.

The invention concerns a method for producing a polyester containing at least one 1,4:3,6-dianhydrohexitol unit comprising:.Math.a step of introducing, into a reactor, monomers comprising at least one monomer (A) that is a diacid or a diester and at least one monomer (B) that is a 1,4:3,6-dianhydrohexitol;.Math.a step of introducing, into the reactor, a catalytic system comprising either a catalyst comprising the element germanium and a catalyst comprising the element aluminum, or a catalyst comprising the elements germanium and aluminum, or a mixture of said two catalysts;.Math.a step of polymerising said monomers to form the polyester;.Math.a step of recovering a polyester composition comprising the polyester and the catalytic system. The invention also concerns a polyester composition containing a catalytic system comprising either a catalyst comprising the element germanium and a catalyst comprising the element aluminum, or a catalyst comprising the elements germanium and aluminum, or a mixture of said two catalysts, and the use of same to reduce the colouring of the polyester.