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Chemical recovery method for waste polycarbonate material

A polycarbonate, easy-to-recycle technology, applied in chemical recovery, chemical instruments and methods, carbonate/haloformate preparation, etc., can solve the problems of harsh high temperature and high pressure conditions, long reaction time, etc., and meet the requirements of equipment conditions low, fast reaction, and mild reaction conditions

Inactive Publication Date: 2009-04-15
QINGDAO UNIV OF SCI & TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a new method of degrading waste polycarbonate with mild conditions, which overcomes the shortcomings of the traditional method of degrading polycarbonate, which requires harsh high temperature and high pressure conditions and long reaction time.

Method used

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  • Chemical recovery method for waste polycarbonate material
  • Chemical recovery method for waste polycarbonate material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Example 1: After pulverizing 50.0 g of waste polycarbonate (particle size ≤ 1 mm), put it into a 250 ml three-necked flask, add 50.0 g of methanol, 1.0 g of sodium hydroxide, and 100.0 g of tetrahydrofuran in sequence, and after the addition is completed, heat the mixture at 40° C. Stirring and reacting for 30 minutes, the reaction solution was subjected to solvent removal, washing, drying and other processes, with a degradation rate of 99%, and 41.7 g of bisphenol A product was obtained with a yield of 92.9%.

Embodiment 2

[0021] Embodiment 2: The experimental conditions and steps are the same as in Embodiment 1, except that tetrahydrofuran is changed to dichloroethane. The degradation rate was 98.6%, and 41.6 g of bisphenol A product was obtained, with a yield of 92.7%.

Embodiment 3

[0022] Embodiment 3: The experimental conditions and steps are the same as in Example 1, except that tetrahydrofuran is changed into a mixture of tetrahydrofuran and dichloroethane, and sodium hydroxide is changed into potassium hydroxide. The degradation rate was 99%, and 41.8g of bisphenol A product was obtained with a yield of 93.1%.

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Abstract

The invention relates to a new method for generating bisphenol A and dimethyl carbonate by solvent waste polycarbonate and chemical degradation waste polycarbonate material under a moderate condition to realize recycling of waste polycarbonate material. The method is characterized in that tetrahydrofuran, drewamine, N-methyl-pyrrolidone, 1, 2-dichloroethane, N, N-dimethyl formamide, diethylamine, ethylene dimine or composite material thereof which are easy to be recycled are used as reaction media, and with the presence of catalysts of sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, lithium hydroxide or composite material thereof, and the like, an alcoholysis reaction is carried out under a normal pressure or a high pressure and at reaction temperature of 20 DEG C-80 DEG C; and a hydrolysis reaction is carried out at reaction temperature of 50 DEG C-160 DEG C. After the reactions, product bisphenol A is obtained (alkyl dimethyl easter product is also obtained in the alcoholysis reaction) after operation processes of solvent removing, washing, drying, and the like are carried out to the reaction liquid. The deterioration rate is over 98 percent. Compared with the traditional methods, the new method for generating bisphenol A and dimethyl carbonate by solvent waste polycarbonate and chemical degradation waste polycarbonate material under a moderate condition to realize recycling of waste polycarbonate material is characterized in that: (1) the reaction conditions are moderate; the reaction speed is high; and the operation is easy and simple; and (2) the problems of long reaction time period and strict requirements for equipment condition existing in the background technology, and the like, are overcome.

Description

technical field [0001] The invention relates to a new method for degrading waste polycarbonate and recovering monomers through a chemical method. technical background [0002] Polycarbonate PC is one of the fastest growing engineering plastics in recent years. Among them, polycarbonate bisphenol A has good properties, such as transparency, heat resistance, impact resistance, etc., and is used in a wide range of industrial applications. Demand continues to expand. Its products have been widely used in electronics, automobiles, clothing, medicine and other industries. With the rapid development of computer and audio-visual industries, the production and demand of PC materials are increasing day by day. At the same time, the amount of waste polycarbonate material produced will increase. Although these waste polycarbonate materials are not very toxic, they not only have a great impact on the environment, but also cause a huge waste of resources due to their bulky size and diff...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C39/16C07C37/52C07C69/96C07C68/00
CPCY02P20/584
Inventor 刘福胜于世涛李卓
Owner QINGDAO UNIV OF SCI & TECH
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