HEUR Polymer Sediment Control via Chelating Additives

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Solution Overview

Problem

Hydrophobically modified ethylene oxide urethane polymers (HEURs) prepared with bismuth catalysts experience undesirable precipitation and color formation during heat aging, posing environmental and quality control challenges.

Innovation Solution

Incorporating citric acid, gluconic acid, or ethylenediamine tetraacetic acid (EDTA) as sediment abating compounds in the polymer solution, with bismuth salt concentrations from 5 to 1000 ppm and sediment abating compound concentrations from 0.05 to 4 weight percent, to minimize sediment and color formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If bismuth catalyst is used to prepare hydrophobically modified alkylene oxide urethane polymer, then environmental acceptability is improved, but precipitation and sedimentation increase

Engineering Contradiction:
Improveenvironmental acceptabilityVSAvoidprecipitation and sedimentation
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent introduces sediment abating compounds (citric acid, gluconic acid, or EDTA salts) as intermediary substances that mediate between the bismuth catalyst and the polymer system. These compounds prevent direct harmful interactions that cause precipitation and sedimentation, allowing the environmentally friendly bismuth catalyst to function without generating the unwanted byproducts.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the chemical parameters of the system by adding sediment abating compounds at specific concentrations (0.05-4 weight percent). This parameter change alters the solution chemistry to prevent precipitation and sedimentation, enabling the use of bismuth catalyst while maintaining product stability.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If bismuth catalyst is used to prepare hydrophobically modified alkylene oxide urethane polymer, then environmental acceptability is improved, but color formation increases

Engineering Contradiction:
Improveenvironmental acceptabilityVSAvoidcolor formation
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

Sediment abating compounds serve as intermediaries that prevent color formation by blocking the chemical pathways that lead to colored byproducts. These compounds interfere with the catalytic cycle in a way that prevents formation of colored species while allowing the bismuth catalyst to remain effective.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the potentially harmful effect of bismuth catalyst into a beneficial process by using sediment abating compounds to channel the catalytic activity toward desired polymerization while preventing unwanted side reactions that cause color formation.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Stability of the object's composition

If sediment abating compound is added to reduce precipitation, then product stability is improved, but solution complexity increases

Engineering Contradiction:
Improveproduct stabilityVSAvoidsolution complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent uses small amounts of sediment abating compounds (0.05-4 weight percent) that act as temporary, disposable additives. These compounds are present in low concentrations and can be easily removed or degraded, minimizing the permanent complexity of the system while providing stable precipitation prevention.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 use of these sediment abating compounds effectively reduces sediment and color formation in HEURs during heat aging, ensuring a stable and environmentally friendly polymer solution.

Implementation Method 1

contacting a hydrophobically modified alkylene oxide urethane polymer with water and at least one sediment abating compound, which is citric acid or a salt thereof, gluconic acid or a salt thereof, or a salt of ethylenediamine tetraacetic acid

Methodology Applied
Scientific EffectChelation:

Implementation Method 2

undesirable color... during heat aging

Methodology Applied
Scientific EffectOxidation inhibition: Oxidation

Data Source

PatentUS10150852B2Process for preparing hydrophobically modified alkylene oxide urethane polymer
Publication Date: 2018.12.11 ROHM & HAAS CO

AI summary

The present invention relates to a composition comprising an aqueous solution of a hydrophobically modified alkylene oxide urethane polymer (HEUR), a bismuth salt, and at least one sediment abating compound selected from the group consisting of citric acid or a salt thereof, gluconic acid or a salt thereof, and a salt of ethylenediamine tetraacetic acid. The composition with the specific sediment abating compounds shows excellent abatement in sediment and color formation in heat age testing of the solution.