CN-121699122-B - Method for preparing high molecular weight polyethylene furandicarboxylate by one-step method

Abstract

The invention discloses a method for preparing high molecular weight polyethylene furandicarboxylate by a one-step method, belonging to the technical field of bio-based polyester materials. The method comprises the steps of weighing raw materials of 2, 5-furandicarboxylic acid, ethylene glycol, a terminal group regulator, a protective agent, a decarboxylation inhibitor and a catalyst, mixing and adding the raw materials into a reaction container, introducing nitrogen, maintaining the nitrogen pressure in the reaction container at 50-150 kPa, carrying out esterification reaction, heating and vacuumizing to less than or equal to 50Pa after the esterification reaction is finished, carrying out polycondensation reaction to obtain a high molecular weight polyethylene furandicarboxylic acid glycol melt, extruding, and drying to obtain the high molecular weight polyethylene furandicarboxylic acid glycol. The FDCA conversion rate of the method is more than or equal to 98%, the number average molecular weight of the obtained product is more than or equal to 32kg/mol, no heavy metal residue exists, and the method is suitable for large-scale production of high-end bio-based packaging materials.

Inventors

• PU XINMING
• CHEN YONG
• SHEN ZHIGANG
• LIANG JINPENG
• QIN YANAN
• YANG LIPING
• XIAO HAIJUN

Assignees

• 万凯新材料股份有限公司

Dates

Publication Date

20260508

Application Date

20260224

Claims (7)

1. 1. A method for preparing high molecular weight polyethylene furandicarboxylate by a one-step process, comprising the steps of: Weighing raw materials of 2, 5-furandicarboxylic acid, ethylene glycol, a terminal group regulator, a protective agent, a decarboxylation inhibitor and a catalyst, mixing and adding the raw materials into a reaction container, introducing nitrogen, maintaining the nitrogen pressure in the reaction container to be 50-150 kPa, carrying out esterification reaction, heating and vacuumizing to be less than or equal to 50Pa after the esterification reaction is finished, carrying out polycondensation reaction to obtain a high molecular weight polyethylene furandicarboxylic acid glycol melt, extruding, and drying to obtain the high molecular weight polyethylene furandicarboxylic acid glycol; the protective agent is a mixed agent formed by compounding 1, 2-propylene glycol and xylitol according to a mass ratio of 4:1; The catalyst is tetrabutyl titanate and zinc acetate with the molar ratio of 2:1; the end group regulator is at least one of p-propylphenol, m-ethylphenol or p-butylphenol; The decarboxylation inhibitor is at least one of erythritol, sorbitol anhydride or maltitol.
2. 2. The process for preparing high molecular weight polyethylene furandicarboxylate according to claim 1, wherein the molar ratio of 2, 5-furandicarboxylic acid to ethylene glycol is 1 (1.2 to 1.7).
3. 3. The method for preparing high molecular weight polyethylene furandicarboxylate by a one-step process as claimed in claim 1, wherein the addition amount of the end group regulator is 0.8 to 3.0% by mass of 2, 5-furandicarboxylic acid; the addition amount of the protective agent is 2.5-5.0% of the mass of the 2, 5-furandicarboxylic acid; the addition amount of the decarboxylation inhibitor is 0.3-1.0% of the mass of the 2, 5-furandicarboxylic acid.
4. 4. The method for preparing high molecular weight polyethylene furandicarboxylate by a one-step process as claimed in claim 1, wherein the addition amount of the end group regulator is 1.2 to 2.0% of the mass of 2, 5-furandicarboxylic acid; the addition amount of the protective agent is 3.0-4.5% of the mass of the glycol; the addition amount of the decarboxylation inhibitor is 0.5% -1.0% of the mass of the 2, 5-furandicarboxylic acid.
5. 5. The method for preparing high molecular weight polyethylene furandicarboxylate according to claim 1, wherein the catalyst is added in an amount of 0.1 to 0.3% by mass of 2, 5-furandicarboxylic acid.
6. 6. A one-step process for preparing high molecular weight polyethylene furandicarboxylate as set forth in claim 1, wherein said starting material further comprises an antioxidant; the antioxidant is at least one of antioxidant 1010, antioxidant 330 or triphenyl phosphite; the addition amount of the antioxidant is 0.1-0.3% of the mass of the 2, 5-furandicarboxylic acid.
7. 7. The method for preparing high molecular weight polyethylene furandicarboxylate by a one-step process as claimed in claim 1, wherein the esterification reaction is carried out at 180-210 ℃ for 2.5-3.5 hours; The conditions of the polycondensation reaction are that the temperature is 220-250 ℃ and the time is 3-4 h.

Description

Method for preparing high molecular weight polyethylene furandicarboxylate by one-step method Technical Field The invention belongs to the technical field of bio-based polyester materials, and particularly relates to a method for preparing high molecular weight polyethylene furandicarboxylate (PEF) by a one-step method, which is particularly applied to the fields of high-barrier bio-based packaging materials, functional films and the like. Background Polyethylene terephthalate (Polyethylene Terephthalate, abbreviated as PET) is a thermoplastic polyester with the largest amount, is easy to process and widely used in the fields of food packaging and the like, but has a short performance board. The core monomer PTA is fully dependent on petroleum, and has insufficient gas barrier and mechanical stability, so the development of a polyester substitute material with better performance and higher environmental compatibility is urgent. As a new generation of bio-based substitute material for PET, the monomer 2, 5-furandicarboxylic acid (FDCA) can be biologically prepared from biomass conversion and Ethylene Glycol (EG), and the furan ring structure gives the PET its oxygen barrier property and mechanical stability superior to PET, and meets the high-end packaging requirement, which is the focus of attention in industry. However, existing PEF production techniques face a production core challenge, resulting in difficulty in obtaining high molecular weight pure PEF by a one-step process. The method is mainly characterized in that (1) FDCA is easy to decarboxylate at high temperature to cause the aggravation of side reaction, (2) the degradation and oxidation of furan rings are accelerated at high temperature to cause the deepening of product color, and (3) EG molecules are subjected to etherification side reaction at high temperature to influence PEF product indexes, EG molecules are dehydrated to generate diethylene glycol at high temperature, and acetaldehyde is generated by intramolecular dehydration. For example, "progress in modified research on biobased polyethylene 2, 5-furandicarboxylate" reports that decarboxylation reaction occurs in FDCA under high-temperature reaction conditions, etherification reaction occurs in FDCA and EG, small molecular impurities such as furancarboxylic acid and furan are generated, and the occurrence of these side reactions leads to the reduction of the utilization rate of FDCA monomers, and also introduces chain termination impurities, which inhibit chain growth, and the final product M n is more or less than 28 kg/mol. The patent 'an antibacterial heat-resistant high-barrier copolyester containing furan ring and a preparation method thereof' proposes a polymerization system of FDCA and cyclic dihydric alcohol, and the pre-esterification temperature is controlled at 160-180 ℃ to avoid the decarboxylation of FDCA through four-stage step polymerization, but the esterification efficiency is reduced due to low temperature, the polymerization time is prolonged, and the problem of the decarboxylation of FDCA is not solved. The patent 'a synthesis method of polyethylene furan dicarboxylate' proposes that a mode of ethylene glycol diacetate is adopted, PEF products are obtained through polymerization by a 'deacetic acid' transesterification method in the later period, and equipment corrosion of acetic acid is not suitable for the prior production technology. In the prior art, FDCA dimethyl ester is also used for polymerization, but the method is used for controlling methanol obtained by esterification reaction, is generally not suitable for industrialization, is free from water and green, and secondly, the method needs alcohol acid ratio of 2:1 to introduce more diethylene glycol, and the final product has low molecular weight and poor performance. In summary, the prior art relies on multi-stage polymerization, which is difficult to meet the requirement of efficient PEF preparation, lacks FDCA decarboxylation and EG ethylene glycol side reaction inhibition schemes, is difficult to optimally break through molecular weight bottlenecks, and does not solve the technical difficulties of the method for preparing high molecular weight PEF by a one-step method. Therefore, the technical scheme for preparing the high molecular weight PEF is developed, the technical difficulties of FDCA decarboxylation and EG side reaction are broken through, the synthetic route of melt polymerization PEF M n is more than or equal to 32 kg/mol and FDCA conversion rate is more than or equal to 98% is realized, and the method has important significance for the development and mass production of bio-based polyester industry and the improvement of the technical competitiveness of the field in China. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to design and provide a method for preparing high molecular weight polyethylene furandicarboxylate (PEF) by a one-step method, which