Recovery process of polyurethane waste

Abstract

The invention discloses a recovery process of polyurethane waste. The recovery process comprises the following steps: (1) adding polyurethane waste, a degradation agent and a catalyst in a reaction kettle, and performing argon shield, placing the system in an oil bath to slowly warm, wherein the degradation agent is selected from a mixture of more than any two of alkyl polyols, the dosage of the degradation agent is 1-3 times of that of the polyurethane waste, the alkyl polyols comprise glycol, propanediol, diethylene glycol, dipropylene glycol, ethanolamine, diglycol and pentaerythritol; (2) stopping heating after keeping the degradation reaction at temperature A and reaction time B when the oil bath temperature is raised to the temperature A; and (3) performing recovery processing on a target reaction product by using the recovery process. By adopting the recovery process disclosed by the invention, the recovery efficiency can be obviously improved, byproducts produced during degradation of the polyurethane waste are reduced, and the recovery cost is lowered.

Description

Technical field [0001] The invention relates to the technical field of polyurethane, in particular to a recycling process of polyurethane waste. Background technique [0002] Polyurethane materials are mainly high molecular polymers prepared from raw materials such as polyisocyanates and polyols. In 2009, my country’s polyurethane production capacity exceeded 4 million tons. The application of a large number of polyurethane products also produced a large amount of waste. Most of the waste was landfilled or incinerated. This not only wasted a lot of reusable resources, but also caused Waste of land and air pollution. How to deal with these polyurethane wastes to realize their recycling has become an issue that must be paid attention to. The types of polyurethane materials involved in the present invention mainly include thermoplastic elastomers (TPE) and cast polyurethane elastomers (CPUE). [0003] Thermoplastic elastomer (TPE) is a material that has both the characteristics of t...

AI Technical Summary

Problems solved by technology

In 2009, my country's polyurethane production capacity exceeded 4 million tons. The application of a large number of polyurethane products also produced a large amount of waste. Most of the waste was landfilled or incinerated. This not only wastes a lot of reusable resources, but also causes waste of land and air pollution

However, since CPU is a thermosetting material, the polymer chains are linked to each other, so it is not easy to recycle, and it is difficult to degrade

[0005] The existing methods of recycling polyurethane waste generally carry out the same recycling treatment for large categories of polyurethane waste, but there are still large differences between various types of polyurethane waste, such as thermoplastic polyurethane elastomer (TPU), cast polyurethane elastomer ( CPUE), if it is treated with the same recycling method, it will lead to poor recycling effect and poor utilization rate

[0006] Patent No. 200410016378.7 discloses "Wet Process Polyurethane Resin Produced Using Waste Polyurethane Shoe Soles". This patent uses a single polyester polyol as a degradation agent, and its degradation efficiency is not ideal

And before adding the degradation agent, it is necessary to add the solvent N,N-dimethylformamide, but N,N-dimethylformamide has the solubility and viscosity-reducing effect, which is extremely corrosive to the human body, Even bring harm to human health and affect the health of reproductive organs

In addition, it uses the solvent N,N-dimethylformamide to dissolve the polyurethane shoe sole into a slurry before degradation, and in the subsequent process of recycling, it is necessary to provide energy for the volatilization of the solvent, which increases energy consumption and equipment resources. and production costs

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