Waste polyurethane recycling technique

Abstract

The invention discloses a waste polyurethane recycling technique. The technique comprises the following steps: pulverizing waste polyurethane into polyurethane particles; adding the polyurethane particles, water, an antioxidant, a decomposer and a catalyst into a reaction kettle, introducing inert gas for protection, heating the reaction kettle in a salt bath, and keeping the conditions of 218-399 DEG C and 50-150 KPa for 3-5 hours to finally obtain diamines, polylols and carbon dioxide, wherein the catalyst is carbodiimide; and separating the diamines and polylols, and the like. The carbodiimide used as the catalyst can promote the product to stratify during reaction in the reaction kettle, enhances the activity of the product and enhances the polyurethane recycling rate, thereby recycling more chemicals with complete types, lowering the required temperature, and being beneficial to saving the production cost.

Description

technical field [0001] The invention relates to the field of waste recycling, in particular to a recycling process for waste polyurethane. Background technique [0002] Polyurethane (referred to as PU) is a polymer made of raw materials such as polyisocyanate, polyol and crosslinking agent. Widely used in automobile manufacturing, refrigerator manufacturing, transportation, civil engineering, footwear, synthetic leather, fabrics, electromechanical, petrochemical, mining machinery, aviation, medical, agriculture and many other fields. [0003] In 2005, the global polyurethane output exceeded 13.75 million tons. With the rapid development of polyurethane, its waste is also increasing. These include a large amount of polyurethane foam used for heat insulation and sofa cushions, waste PU shoe soles, waste PU leather, etc. If these wastes are only disposed of by landfill and incineration, it will not only occupy land, but also pollute the environment, and it is also a waste of...

AI Technical Summary

Problems solved by technology

[0008] The added value of the product prepared by the physical method is low, and the method of recovering heat energy is likely to cause secondary pollution

Among the chemical methods, the polyols produced by the hydrolysis method are difficult to purify and the cost is high; the alkali hydrolysis method has a long process and high cost; the product components obtained by the aminolysis method are complex, which is not conducive to recycling; relatively high temperature