A method for preparing recycled flame-retardant polyester by alcoholysis of waste polyester

A flame-retardant polyester and waste polyester technology, applied in the field of waste polyester recycling, can solve the problems of large fluctuations in the content of diethylene glycol by-products, poor hue of recycled polyester, and difficult control of melting point, etc., to achieve stable alcohol Improve product quality, reduce by-products, and achieve high-value recycling

Active Publication Date: 2019-10-11
ZHEJIANG SCI-TECH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] However, in the above methods of obtaining ethylene terephthalate or oligomers through alcoholysis of ethylene glycol, and then performing polycondensation, due to the uncertainty of the source of raw materials, the hue of the recycled polyester will become poor, and the by-product diglycol The content of alcohol (DEG) fluctuates greatly, and the melting point is not easy to control, which reduces the quality of the product

Method used

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  • A method for preparing recycled flame-retardant polyester by alcoholysis of waste polyester
  • A method for preparing recycled flame-retardant polyester by alcoholysis of waste polyester

Examples

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Embodiment 1

[0017] A kind of waste polyester alcoholysis method of the present embodiment prepares the method for regenerated flame-retardant polyester, such as figure 1 As shown, it includes the following steps: 1) pretreatment of waste polyester, directly smashing the clean waste polyester blocks into the feed bin, cutting the clean waste polyester fibers into the feed bin, and waste polyester bottle flakes Sorting, cleaning, impurity removal, crushing, cutting, and then feeding into the silo, and then mixing ingredients for the next process; 2) alcoholysis of waste polyester, the pretreated waste polyester, according to waste polyester (waste polyester) The molar percentage ratio of 1:2 is put into the alcoholysis kettle 1, and the alcoholysis kettle 1 contains ethylene terephthalate and oligomer (mother liquor) (adding in the first additive inlet 8), wherein the addition of ethylene terephthalate and oligomer (mother liquor) accounts for 40% of the total mass percentage of dropping in...

Embodiment 2

[0020]As described in Example 1, the difference is: the molar percentage of waste polyester and ethylene glycol is 1:4, and the alcoholysis still contains ethylene terephthalate and oligomers (mother liquor), wherein the The addition amount of ethylene glycol diformate and oligomer (mother liquor) accounted for 30% of the total mass percentage of input waste polyester, the reaction temperature was 200° C., and the reaction time was 4 hours. Add 0.2‰ (accounting for the mass percent of the product obtained) of phosphorous acid stabilizer; the esterification reaction temperature is 230 ° C, the reaction time is 1.5 hours, and the CEPPA-EG solution with a phosphorus content of 0.8% (accounting for the mass percent of the obtained product) is added at the same time, 0.3% (accounting for the mass percent of the obtained product) of DEG, so that the DEG content (accounting for the obtained product mass percent) of the esterified product is 2.9%. The temperature of polycondensation-I...

Embodiment 3

[0023] As described in Example 1, the difference is: the molar percentage of waste polyester and ethylene glycol is 1:6, and the alcoholysis still contains ethylene terephthalate and oligomers (mother liquor), wherein the The addition amount of ethylene glycol diformate and oligomer (mother liquor) accounted for 20% of the total mass percentage of input waste polyester, the reaction temperature was 190° C., and the reaction time was 2 hours. Add the trimethyl phosphate stabilizer of 0.2‰ (accounting for the mass percent of the product obtained); the esterification reaction temperature is 220°C, the reaction time is 1 hour, and the CEPPA-EG solution with a phosphorus content of 1.0% (accounting for the mass percent of the product obtained) is added simultaneously, 0.2% (accounting for the mass percent of the obtained product) of DEG, so that the DEG content in the esterified product (accounting for the obtained product mass percent) is 3.0%. The temperature of polycondensation-...

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Abstract

The invention discloses a method for preparing regenerated flame-retardant polyester through a waste polyester alcoholysis process. The method comprises the following steps: 1) pretreating waste polyester; 2) performing alcoholysis on waste polyester; 3) controlling the quality of a compound ester, and taking an ethylene glycol solution of 2-carboxyethylphosphinicacid as a comonomer to be added; 4) performing condensation polymerization and preparing chips, wherein the intrinsic viscosity of the finally obtained regenerated flame-retardant polyester is 0.60-0.70dl / g, the melting point is 230-240 DEG C, the content of diethylene glycol is 3.5+ / -0.3%, the chroma value b is less than 8, and the limit oxygen index is 28-34%. The regenerated flame-retardant polyester prepared by the method disclosed by the invention is high in limit oxygen index and excellent in flame-retardant property and can be used for preparing flame-retardant polyester filaments and short fibers, and high-valued recycling of the waste polyester is realized.

Description

technical field [0001] The invention relates to a method for preparing regenerated flame-retardant polyester by alcoholysis of waste polyester, which belongs to the field of recycling and utilization of waste polyester. Background technique [0002] Polyethylene terephthalate (PET, polyester for short), as an important raw material, is widely used in the production of beverage bottles, fibers, films, sheets, etc. With the rapid development of the polyester industry, the polyester waste produced during the production of polyester and the processing and use of its products is also increasing rapidly. Due to the strong chemical inertness of polyester, it is difficult to degrade or be decomposed by microorganisms in natural storage, which not only causes a huge waste of resources, but also produces serious environmental pollution. Therefore, realizing a virtuous cycle of resources and improving environmental quality through recycling has become an important issue in the current...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G63/78C08G63/692
Inventor 王秀华陈文兴张须臻胡园超
Owner ZHEJIANG SCI-TECH UNIV
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