Polyamide Amorphization in Salt Solution for Mild Depolymerization

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Solution Overview

Problem

Current methods for depolymerizing semi-crystalline polyamides require harsh conditions due to the crystallites hindering catalyst mobility, leading to energy-intensive processes and insufficient quality for recycling in demanding industries like automotive.

Innovation Solution

A process involving amorphization of polyamides by immersing the material in a salt solution with pH ≤ 7 and temperature ≥ 20°C, followed by adjusting the pH to ≥ 4 in a salt solution with ≥ 10% mass concentration, stabilizing the amorphous state for enzymatic depolymerization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If harsh conditions (strong acids and high-temperature heating above melting point) are applied for depolymerization, then depolymerization efficiency is improved, but energy consumption increases and process complexity increases

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

Solution Approach 1:

The invention changes the physical state parameter of the polyamide from semi-crystalline to amorphous before depolymerization. This parameter change allows the process to proceed at lower temperatures (below melting point) and with milder chemical conditions, thereby reducing energy consumption while maintaining depolymerization efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention performs amorphization as a preliminary step before depolymerization. By transforming the polyamide into an amorphous state first, the subsequent depolymerization process can occur under milder conditions, avoiding the need for harsh high-temperature heating and reducing overall energy requirements

Inventive Principle:
Principle #10Preliminary action

2Productivity

If harsh conditions (strong acids and high-temperature heating) are applied for depolymerization, then depolymerization efficiency is improved, but process complexity increases

Engineering Contradiction:
Improvedepolymerization efficiencyVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention changes the physical state parameter of the polyamide from semi-crystalline to amorphous before depolymerization. This parameter change allows the process to proceed at lower temperatures and with milder chemical conditions, thereby reducing process complexity while maintaining depolymerization efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention performs amorphization as a preliminary step before depolymerization. By transforming the polyamide into an amorphous state first, the subsequent depolymerization process can occur under milder conditions, simplifying the overall process workflow and reducing the need for complex high-temperature equipment and harsh chemical handling

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If the material remains in semi-crystalline state, then structural stability is maintained, but catalyst mobility is hindered and depolymerization efficiency decreases

Engineering Contradiction:
Improvestructural stabilityVSAvoiddepolymerization efficiency
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The invention changes the physical state parameter of the polyamide from semi-crystalline to amorphous. This transformation eliminates crystalline structures that hinder catalyst mobility, thereby improving depolymerization efficiency while the amorphous state itself provides a different form of stability suitable for the depolymerization process

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 amorphization process enables gentler and environmentally friendly depolymerization pathways, preserving the amorphous nature of polyamides for effective recycling.

Implementation Method 1

maintain the material in said solution S1 until amorphization of the polymer

Methodology Applied
Scientific EffectAmorphization: Phase Change

Implementation Method 2

adjust the pH of the solution S1 to a pH greater than or equal to 4 or transfer the material obtained into a solution S2 containing at least one salt and having a pH greater than or equal to 4

Methodology Applied
Scientific EffectpH stabilization:

Data Source

PatentEP4700066A1Method for amorphizing a material comprising a polymer
Publication Date: 2026.02.25 RENAULT SA
  • EP4700066A1 patent drawingFigure 1~2
  • EP4700066A1 patent drawingFigure 3~4
  • EP4700066A1 patent drawingFigure 5

AI summary

The present invention relates to a method for amorphizing a material comprising at least one polymer, comprising the following steps: a) adding the material to a solution S1 containing at least one salt and having a pH less than or equal to 7; b) exposing the solution S1 to a temperature T1 greater than or equal to 20°C; c) maintaining the material in said solution S1 until the polymer is amorphized; d) adjusting the pH of the solution S1 to a pH greater than or equal to 4 or transferring the material obtained into a solution S2 containing at least one salt and having a pH greater than or equal to 4 and in which the mass concentration of salt is greater than or equal to 10% by weight relative to the total weight of the solution S2.