Low-temperature depolymerization of polymer containing urethane functional group using cosolvent and method for producing polyol

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing polyurethane recycling methods, particularly chemical recycling, face challenges such as high energy consumption, low-quality recycled products, and complex purification processes due to high-temperature depolymerization, leading to environmental and economic inefficiencies.

Innovation Solution

A depolymerization composition comprising a compound with two or more alcohol functional groups and an aromatic compound with one or more alkoxy functional groups, along with a catalyst, is used to break urethane bonds at low temperatures, facilitating rapid and selective depolymerization with minimal side reactions, followed by simple phase separation to obtain high-quality polyol.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-temperature depolymerization is used to recycle polyurethane, then depolymerization efficiency is improved, but energy consumption increases and product quality deteriorates

Engineering Contradiction:
Improvedepolymerization efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The invention changes the temperature parameter from high-temperature (conventional) to low-temperature (100-200°C) depolymerization by introducing a co-solvent system comprising aromatic compounds with alkoxy groups combined with polyhydric alcohols. This parameter change enables efficient depolymerization at lower temperatures, resolving the contradiction between depolymerization efficiency and energy consumption.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces aromatic compounds with alkoxy groups as intermediary co-solvents that facilitate the depolymerization reaction. These co-solvents act as mediators between the polyhydric alcohol and polyurethane, enabling the reaction to proceed efficiently at low temperatures through enhanced solvation and catalytic effects, thus improving efficiency without increasing energy consumption.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If high-temperature depolymerization is used, then depolymerization rate is improved, but product purity deteriorates due to side reactions

Engineering Contradiction:
Improvedepolymerization rateVSAvoidproduct purity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

By changing the temperature parameter to low-temperature range (100-200°C) and introducing aromatic co-solvents, the invention suppresses side reactions that occur at high temperatures. The co-solvent system modifies the reaction environment to favor selective depolymerization, achieving high product purity while maintaining efficient depolymerization rates.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Aromatic compounds with alkoxy groups serve as intermediary co-solvents that create a favorable reaction environment. They enhance the selectivity of the depolymerization reaction by improving solvation of transition states and stabilizing intermediates, thereby increasing product purity without sacrificing depolymerization rate.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If conventional depolymerization methods are used, then processing is simplified, but purification process complexity increases

Engineering Contradiction:
Improveprocessing simplicityVSAvoidpurification process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The aromatic co-solvents act as intermediaries that facilitate easy separation of the polyol product. After depolymerization, the co-solvent system allows for simple phase separation and filtration to obtain high-purity polyol, avoiding complex purification processes such as multiple distillations or chromatographic separations required by conventional methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Use of energy by moving object

If low-temperature depolymerization is used, then energy consumption is reduced, but depolymerization rate decreases

Engineering Contradiction:
Improveenergy consumptionVSAvoiddepolymerization rate
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

Aromatic compounds with alkoxy groups serve as intermediary co-solvents that compensate for the lower thermal energy available at low temperatures. They enhance the reaction rate through improved solvation, stabilization of transition states, and catalytic effects, enabling fast depolymerization at low temperatures and thus resolving the contradiction between energy consumption and depolymerization rate.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

By changing the chemical environment parameter through introduction of aromatic co-solvents, the invention compensates for the reduced thermal energy at low temperatures. The co-solvent system modifies the reaction kinetics to maintain high depolymerization rates despite lower temperature, achieving both low energy consumption and high productivity.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method enables efficient, low-temperature depolymerization of polyurethane to produce high-purity polyol, reducing energy consumption and operational costs while allowing for the production of high-quality recycled materials suitable for reuse.

Implementation Method 1

a compound having two or more alcohol functional groups is added as a depolymerization solvent for decomposing a polymer containing a urethane functional group

Methodology Applied
Scientific EffectDepolymerization:

Implementation Method 2

break urethane bonds at low temperatures, facilitating rapid and selective depolymerization

Methodology Applied
Scientific EffectChemical Bonding:

Implementation Method 3

through a physical separation process of the reaction products thus obtained, high-quality recycled polyol can be obtained

Methodology Applied
Scientific EffectPhase separation:

Data Source

PatentEP4650393A1Low-temperature depolymerization of polymer containing urethane functional group using cosolvent and method for producing polyol
Publication Date: 2025.11.19 KOREA RES INST OF CHEM TECH
  • EP4650393A1 patent drawingFigure 1
  • EP4650393A1 patent drawingFigure 2
  • EP4650393A1 patent drawingFigure 3

AI summary

The present invention relates to a low-temperature depolymerization of a polymer containing a urethane functional group using a co-solvent and to a method for producing a polyol. More specifically, the invention concerns adding a compound having two or more alcohol functional groups as a depolymerization solvent for decomposing a polymer containing a urethane functional group, and adding an aromatic compound having an alkoxy functional group as a co-solvent to construct a reaction system for decomposing the polymer containing a urethane functional group. This enables rapid depolymerization at a low temperature, and through a physical separation process of the reaction products generated therefrom, a high-quality regenerated polyol can be obtained at a high yield.