Preparation method of bio-based 2,5-FDCA (furandicarboxylic acid)-based copolyester

Abstract

The invention relates to a preparation method of a bio-based 2,5-FDCA (furandicarboxylic acid)-based copolyester. Dibasic acid, aliphatic diol I, a primer and a Ti-Si-Co composite catalyst are uniformly mixed and sequentially subjected to an esterification reaction, a pre-condensation polymerization reaction and a final condensation polymerization reaction, and the bio-based 2,5-FDCA-based copolyester is prepared; the primer is ester produced through a reaction of bio-based 2,5-FDCA and aliphatic diol II, the molar ratio of dibasic acid to aliphatic diol I is 1:(1.05-1.10), the Ti-Si-Co composite catalyst is formed by compositing a Ti-Si composite catalyst and a Co catalyst, the Ti-Si composite catalyst is obtained through supporting of a Ti catalyst on a Si catalyst, and the aliphatic diol I and the aliphatic diol II are the same or different. The preparation method has few side reactions and high reaction rate, and the prepared product has concentrated molecular weight distribution,high viscosity, good quality and great application prospects.

Description

technical field [0001] The invention belongs to the field of polyester preparation, and relates to a preparation method of bio-based 2,5-furandicarboxylic acid-based copolyester, in particular to a bio-based 2,5-furandicarboxylic acid-based polyacid-aliphatic dihydric alcohol Process for the preparation of copolyesters. Background technique [0002] Polyester refers to the general term for polymers obtained by polycondensation of polyols and polyacids. It mainly refers to polyethylene terephthalate (PET), and customarily also includes linear thermoplastic resins such as polybutylene terephthalate (PBT) and polyarylate. It is a kind of polymer with excellent performance and wide application. At present, it has been widely used in fiber, plastic, film and other fields. Compared with petroleum-based PET, the monomer 2,5-FDCA of PEF is derived from bio-based resources, which can reduce the use of non-renewable resources (NREU) and greenhouse gas (GHG) emissions. With the rap...

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Problems solved by technology

[0007] The following problems exist in the preparation of existing bio-based 2,5-furandicarboxylic acid-based polyesters: 1) The molar ratio of bio-based 2,5-furandicarboxylic acid to glycol-alkyd acid in the existing technical system is much higher At a ratio of 1:1, diols undergo self-condensation at a high alkyd molar ratio to generate by-products, which have a greater impact on the fiber-forming properties of polyester. At the same time, high molar ratios require more diol raw materials to be consumed. 2) For polyester, the esterification stage is directly related to the quality of the final polycondensation product. Although bio-based 2,5-furandicarboxylic acid has a very similar structure to terephthalic acid, its thermal stability decreases. The existing technology needs to carry out sufficient esterification reaction under the esterification time of more than 3 hours under the high alkyd-acid molar ratio, and this very easily causes the generation of side reaction in the esterification process; Polycondensation and final polycondensation reactions can produce polyester. The intrinsic viscosity of the pre-condensation product is generally above 0.25dL / g, which results in a wide molecular weight distribution of the final product and poor processability, which is easily produced during processing. Phenomena such as wool, broken ends, waste silk, etc.

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