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.

The present invention relates to a tape comprising a composition comprising a copolyester comprising 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.

A bi-profiled fiber and preparing method thereof are provided. The bi-profiled fiber is manufactured through the steps of spinning melt metering, extruding via the composite spinneret, cooling, oiling, drawing, heat setting and winding, finally containing both double-cross monofilaments and circular monofilaments simultaneously. The bi-profiled fiber is made of the modified polyester, and the modified polyester is dispersed by matte agent and is composed of terephthalic acid segments, ethylene glycol segments and branched diol segments, and the branched diol segment has a structural formula of

##STR00001## where R.sub.1 and R.sub.2 are separately selected from the linear alkylene with 1-3 carbon atoms, R.sub.3 from the alkyl with 1-5 carbon atoms, and R.sub.4 from the alkyl with 2-5 carbon atoms. The matte agents is a mixture of amorphous titanium dioxide and amorphous silicon dioxide, or a mixture of calcium carbonate and amorphous silicon dioxide.

The present invention discloses a method for preparing a functionalized organic magnesium salt. The method includes completely dissolving organic acid in distilled water to form an organic acid aqueous solution, adding an inorganic magnesium salt into the organic acid aqueous solution, magnetically stirring for 1-5 h at 70-100 C., removing distilled water, and performing vacuum drying to obtain a white powdery solid which is a functionalized organic magnesium salt. An intrinsic flame-retardant PET composite material prepared by using the functionalized organic magnesium salt as a flame retardant not only achieves the compatibility between inorganic particles and a matrix, but also solves the problem of poor flame retardant performance of PET plastics in the existing production process.

The present invention provides a method for manufacturing textile waste into fiber grade polyester chips applicable to textile processing. The method comprises textile waste crushing, alcoholysis, filtering and separation, cooling crystallization, pressing, decoloration, distillation purification, preheating, prepolycondensation, polycondensation, cooling strip casting, and cutting into particles. By reducing textile waste to high purity bis(2-hydroxyethyl)terephthalate (hereinafter referred to as BHET), fiber grade polyester chips applicable to textile processing are re-manufactured. Thus, efficient recycling is achieved.

The present invention relates to: a biodegradable polyester resin prepared by adding a reaction rate control agent and a molecular weight increasing agent which are derived from biomass; and a method for preparing the same and, more specifically, to a biodegradable polyester resin and a method for preparing same, in which, to obtain a biodegradable polyester resin having a reaction rate, flexibility and tensile strength which are superior to those of polybutylene-co-adipate terephthalate, which is a conventional biodegradable polyester resin, polyglycerol succinate having a number average molecular weight of 500-1,000, prepared by synthesis through an esterification reaction between glycerol and succinic acid, is added as a reaction rate control agent derived from biomass to increase the reaction rate in the synthesis of a biodegradable polyester resin, and polyglycerol furanoate having a number average molecular weight of 1,000-5,000, prepared by synthesis through an esterification reaction between glycerol and 2,5-furandicarboxylic acid, is added as a molecular weight increasing agent derived from biomass to increase tensile strength, to thereby prepare a biodegradable polyester resin having a number average molecular weight of 70,000 or more, a weight average molecular weight of 150,000 or more, an acid value of 0.4-0.8 mg-KOH/g, and a tensile strength of 400 kgf/cm.sup.2 or more.

A polyethylene terephthalate composition (PET), an injection-molded bottle preform made from a PET composition, a refillable PET container blow-molded from the preform, catalyst compositions used for making the PET composition, methods for making the PET composition, methods for injection-molding a PET bottle preform, methods for blow-molding a refillable PET bottle from a preform and methods for improving the rewash stability and recyclability of refillable PET bottles particularly for carbonated soft drinks.

A process for producing a cationic dyeable polyester includes the steps of: (a) subjecting a combination of a bis-hydroxy alkyl terephthalate monomer of Formula (1) defined herein and an organic diacid monomer mixture which includes an aromatic dicarboxylic acid monomer and a sulfo group-containing aromatic dicarboxylic acid dyeable monomer to an esterification reaction to form an esterification reaction product; and (b) subjecting the esterification reaction product to a polycondensation reaction.

A high-strength thermal-stability polyester industrial yarn is prepared by spinning, winding and coordination treatment of a modified polyester after a solid-state polycondensation; wherein the method of coordination treatment comprises: soaking the wound fiber in an aqueous solution of a coordination agent, and the concentration of the aqueous solution of the coordination agent is 0.1-0.2 mol/L; wherein the condition of coordination treatment is 48-72 hours at 80-100 C., and the concentration of the aqueous solution of the coordination agent is 0.1-0.2 mol/L; wherein the polyester segments of the prepared high-strength thermal-stability polyester industrial yarn comprises a terephthalic acid segment, an ethylene glycol segment and a 2,6-pyridinedicarboxylic acid segment, and 2,6-pyridinedicarboxylic acid segments of different polyester segments are coordinated by Fe.sup.3+, the molar ratio of the terephthalic acid segment to the 2,6-pyridinedicarboxylic acid segment is 1:(0.03-0.05).

The present invention relates to a method for preparing polymers, in particular to a method for preparing a polymer comprising constitutional units derived from bis(2-hydroxyethyl) terephthalate (BHET). The BHET used in the method is a high quality recycled BHET product, which allows plastic preparation methods in which the BHET is used to be simplified.