Method for recycling polyester waste by normal-pressure alcoholysis

A technology of atmospheric pressure alcohol and waste, applied in the fields of recycling technology, plastic recycling, chemical instruments and methods, etc., can solve the problems of ethylene glycol difficult to recycle, difficult to recycle, environmental pollution, etc., to reduce production costs and equipment requirements The effect of low and shortened process

Inactive Publication Date: 2010-12-08
SICHUAN UNIVERSITY OF SCIENCE AND ENGINEERING
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  • Summary
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  • Description
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Problems solved by technology

The disadvantages of the acid hydrolysis method are: the reaction consumes a large amount of concentrated acid and strong alkali, which is difficult to recycle, easily causes environmental pollution, and the ethylene glycol produced is also difficult to recycle.
However, like the above-mentioned chemical method, this method degrades waste PET into monomers, and there are still problems of complicated process and high cost

Method used

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  • Method for recycling polyester waste by normal-pressure alcoholysis
  • Method for recycling polyester waste by normal-pressure alcoholysis
  • Method for recycling polyester waste by normal-pressure alcoholysis

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Embodiment Construction

[0026] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0027] Polyester is formed by esterification and polycondensation of terephthalic acid and ethylene glycol. The monomers or low molecular polymers obtained by reverse reaction alcoholysis under the action of catalyst and ethylene glycol can be used as unsaturated polyesters. Raw materials, then add saturated or unsaturated dibasic acid and ethylene glycol, and undergo esterification and polycondensation to obtain unsaturated polyester resin.

[0028] The invention uses polyester (PET) waste (including its products) as raw material, ethylene glycol (EG) as degradation agent, zinc acetate (Zn(OAc) 2 ) as a catalyst for alcoholysis, and the alcoholysis is carried out under normal pressure.

[0029] The specific steps are:

[0030] 1) Material preparation - weighing polyester waste m 1 , and prepare materials according to the mass ratio of polyester waste, eth...

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Abstract

The invention discloses a method for recycling polyester waste by normal-pressure alcoholysis, which comprises the following steps: 1) preparing polyester waste, glycol and zinc acetate; 2) adding the prepared materials into a reactor, introducing inertia gas for protection, heating to 180 to 197.5 DEG C with stirring, and keeping the temperature for 5 to 9 hours; 3) after keeping the temperature, cooling to 90 to 105 DEG C, and filtering the hot materials under vacuum to remove non-degraded polyester waste; 4) refrigerating the filtrate at 5 DEG C for 5 to 10 hours to allow the degradation products to precipitate in form of crystals, and filtering under vacuum; and 5) drying the crystallization product under vacuum to obtain a recycled product. The method shortens flow, reduces production cost, protects environment, realizes chemical recycling, changes waste into valuable material and saves resources. The method has the advantages of simple reaction conditions, easy implementation, normal-pressure operation, low equipment requirements and low recycling cost.

Description

technical field [0001] The invention relates to a method for recycling waste materials, in particular to a method for recycling polyester waste materials through an alcoholysis process under normal pressure. Background technique [0002] Polyethylene terephthalate (PET, polyester for short) is an important industrial raw material, and its main products include beverage bottles, fibers, films, film bases, electrical insulation materials and engineering plastics, etc., polyethylene terephthalate Ethylene glycol ester is obtained by homopolymerization of ethylene terephthalate, or by polymerization of terephthalic acid and ethylene glycol. With the sharp increase in the annual output of polyester products, the polyester wastes brought by polyester products are also increasing rapidly. In addition, in the process of forming polyester products, various scrap products and leftovers are often produced. Due to the strong chemical inertness of polyethylene terephthalate, it is dif...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08J11/24C07C69/82C07C67/00
CPCY02W30/62
Inventor 喻兰英李新跃张敬雨罗红孙亚丽
Owner SICHUAN UNIVERSITY OF SCIENCE AND ENGINEERING
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