Modified polyester and preparation method thereof

A modified polyester and esterification technology, applied in the field of polyester, can solve the problems of low dyeing rate, small increase in free volume, high melt viscosity of PET fibers, etc., to increase the degree of diffusion, increase free volume, The effect of improving dyeing performance

Active Publication Date: 2017-02-08
JIANGSU HENGLI CHEM FIBER
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, the molecular chains of PET are regular, the crystallinity is good, the molecular chains are closely arranged, and there are no polar groups that interact with dye molecules on the molecular chains, which makes the coloring of PET fibers more difficult.
[0005] Therefore, the usual PET fiber dyeing is generally under high temperature and high pressure, and disperse dyes are selected for dyeing. When the temperature reaches above the glass transition temperature of PET fiber, the increase in free volume is small, the dyeing rate is not high, and the dyeing performance is poor.
Therefore, the energy consumption and low dyeing rate brought by the high temperature and high pressure method are the main problems now.
In addition, the melt viscosity of PET fiber is high, which is not conducive to processing

Method used

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  • Modified polyester and preparation method thereof
  • Modified polyester and preparation method thereof
  • Modified polyester and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] A preparation method of modified polyester, specifically comprising the following steps:

[0043] (1) Preparation of glycol terephthalate:

[0044] Put terephthalic acid and 2-pentyl-1,3 propanediol with a molar ratio of 1:1.3 into a slurry and add it to the reactor at a concentration of 50 wt%, and the addition amount is 0.3% of the weight of terephthalic acid. Under the catalysis of sulfuric acid, esterification reaction is carried out. The esterification reaction is pressurized in a nitrogen atmosphere. The pressurized pressure is normal pressure and the temperature is 180°C. Time is the end point of the esterification reaction to obtain diol terephthalate;

[0045] (2) Preparation of ethylene terephthalate:

[0046] Terephthalic acid and ethylene glycol with a molar ratio of 1:1.2 are made into a slurry and then added to the reactor for esterification reaction. The esterification reaction is pressurized in a nitrogen atmosphere. The pressurized pressure is normal ...

Embodiment 2

[0051] A preparation method of modified polyester, specifically comprising the following steps:

[0052] (1) Preparation of glycol terephthalate:

[0053] Put terephthalic acid and 2-hexyl-1,3 propanediol with a molar ratio of 1:1.38 into a slurry and add to the reactor, at a concentration of 55wt%, add concentrated sulfuric acid in an amount of 0.32% of the weight of terephthalic acid Under the catalysis of the catalyst, the esterification reaction is carried out. The esterification reaction is pressurized in a nitrogen atmosphere. The pressurized pressure is 0.13 MPa and the temperature is 181 °C. For the end point of the esterification reaction, obtain diol terephthalate;

[0054] (2) Preparation of ethylene terephthalate:

[0055] Put terephthalic acid and ethylene glycol into a slurry with a molar ratio of 1:1.3 and add them into the reactor to carry out esterification reaction. The esterification reaction is pressurized in a nitrogen atmosphere. The pressurized pressur...

Embodiment 3

[0060] A preparation method of modified polyester, specifically comprising the following steps:

[0061] (1) Preparation of glycol terephthalate:

[0062] Put terephthalic acid and 2-heptyl-1,3 propanediol with a molar ratio of 1:1.33 into a slurry and add it to the reactor at a concentration of 60 wt%, and the addition amount is 0.33% of the weight of terephthalic acid. Under the catalysis of sulfuric acid, esterification reaction is carried out. The esterification reaction is pressurized in a nitrogen atmosphere. The pressurized pressure is 0.12 MPa and the temperature is 183 ° C. When the amount of water distilled in the esterification reaction reaches 92% of the theoretical value Time is the end point of the esterification reaction to obtain diol terephthalate;

[0063] (2) Preparation of ethylene terephthalate:

[0064] Put terephthalic acid and ethylene glycol into a slurry with a molar ratio of 1:1.31 and put them into the reactor to carry out esterification reaction....

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PUM

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Abstract

The invention relates to a modified polyester and a preparation method thereof. The modified polyester is composed of a terephthalic acid segment, a glycol segment, and a branch chain containing dihydric alcohol segment. The branch chain of the branch chain containing dihydric alcohol segment is positioned on one non-terminal carbon of the branch chain containing dihydric alcohol segment, is a straight carbon chain, and contains 5 to 10 carbon atoms. The preparation method comprises the following steps: carrying out esterification reactions between terephthalic acid and branch chain containing dihydric alcohol in the presence of concentrated sulfuric acid to obtain dihydric alcohol terephthalate; then carrying out esterification reactions between terephthalic acid and glycol to obtain ethylene terephthalate; stirring and mixing dihydric alcohol terephthalate and ethylene terephthalate, in the presence of a catalyst and a stabilizing agent, and carrying out condensation reactions in a low vacuum stage and a high vacuum stage to obtain modified polyester. The increased space between the gaps among molecular chains in polyester is far greater than that of branch chain free polyester at a same temperature, so small particles such as dye can more easily enter the interior of modified polyester, and the dyeing speed is increased.

Description

technical field [0001] The invention belongs to the technical field of polyester, and relates to a modified polyester and a preparation method thereof. Background technique [0002] Since its inception, polyethylene terephthalate (PET fiber or polyester fiber) fiber has high breaking strength and elastic modulus, moderate resilience, excellent heat setting, good heat resistance and light resistance, acid resistance, alkali resistance and corrosion resistance. It has a series of excellent performances such as anti-wrinkle and anti-wrinkle, good stiffness, etc. It is widely used in clothing, home textiles and other fields. [0003] However, due to the high crystallinity and compact structure of PET, and there is no functional group combined with the dye on the molecular chain, it is difficult for the dye molecule to enter the fiber and dyeing is difficult. Can't satisfy people to bright-coloured beautiful, the fabric demand of unique style. [0004] The reason for the diffic...

Claims

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Application Information

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IPC IPC(8): C08G63/183C08G63/78
CPCC08G63/183C08G63/78D01F6/84D06P3/54C08G63/81D01F6/62
Inventor 范红卫刘志立李文刚汤方明王丽丽尹立新
Owner JIANGSU HENGLI CHEM FIBER
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