Purifying Polyether-Carbonate Polyols with Solid Absorbents

Solution Overview

Problem

Existing methods for removing cyclic alkylene carbonate impurities from polyether-carbonate polyols are capital intensive and expose the polyols to elevated temperatures, leading to thermal degradation.

Innovation Solution

A process involving contacting polyether-carbonate polyols with a solid absorbent at moderately elevated temperatures (30-150°C) to effectively remove cyclic alkylene carbonates using porous materials like alumina, magnesium silicate, or ion exchange resins, minimizing thermal degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vaporization or stripping under reduced pressure is used to remove cyclic alkylene carbonate, then the impurity removal is effective, but the process becomes capital intensive and exposes polyols to elevated temperatures causing thermal degradation

Engineering Contradiction:

Improveimpurity removal effectivenessVSAvoidthermal degradation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs porous ion exchange resins as absorbents to remove cyclic alkylene carbonate from polyether-carbonate polyols. The porous structure provides high surface area for adsorption while the ion exchange capability enables selective removal of impurities through ionic interaction, achieving effective impurity removal without requiring elevated temperatures or complex equipment

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent introduces ion exchange resins as intermediary substances that mediate the removal of cyclic alkylene carbonate. These resins act as a bridge between the polyol and the impurity, selectively absorbing the carbonate through ion exchange mechanisms while leaving the polyol intact, thus avoiding direct thermal exposure

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If vaporization or stripping under reduced pressure is used to remove cyclic alkylene carbonate, then the impurity removal is effective, but the process becomes capital intensive

Engineering Contradiction:

Improveimpurity removal effectivenessVSAvoidprocess complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs porous ion exchange resins as absorbents to remove cyclic alkylene carbonate from polyether-carbonate polyols. The porous structure provides high surface area for adsorption while the ion exchange capability enables selective removal of impurities through ionic interaction, achieving effective impurity removal without requiring elevated temperatures or complex equipment

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent utilizes ion exchange resins that can be easily disposed of or regenerated, replacing the need for expensive and complex vaporization or stripping equipment. The resin beads can be discarded after use or regenerated through simple washing processes, significantly reducing capital investment requirements

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If treatment with strong base or oxidation is used to convert catalyst residues to ionic species, then the impurity removal is effective, but the process complexity and cost increase

Engineering Contradiction:

Improvecatalyst residue removalVSAvoidprocess complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces ion exchange resins as intermediary substances that mediate the removal of catalyst residues. These resins provide a gentle ionic exchange mechanism that converts and removes catalyst residues without requiring strong bases or oxidation processes, simplifying the overall process while maintaining effectiveness

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This process efficiently removes cyclic alkylene carbonates in a cost-effective and time-efficient manner with minimal thermal degradation, preserving the polyether-carbonate polyols for use in various applications.

Implementation Method 1

contacting a starting polyether-carbonate that contains at least 0.25 weight-%, based on the weight of the starting polyether-carbonate, of one or more cyclic alkylene carbonates, with a solid absorbent

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 2

contacting a starting polyether-carbonate that contains at least 0.25 weight-%, based on the weight of the starting polyether-carbonate, of one or more cyclic alkylene carbonates, with a solid absorbent

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Data Source

PatentUS12146027B2Purification process for polyether-carbonate polyols

Publication Date: 2024.11.19 DOW GLOBAL TECHNOLOGIES LLC

AI summary

Alkylene carbonates are removed from polyether-carbonate polymers by contacting the polyether-carbonate with an absorbent at a temperature of 30 to 150° C. The process is effective and inexpensive. The purified polyether-carbonate is useful for making polyurethanes as well as in many other applications.