Polymer Dispersion Stability via Sulfate Phosphate Salt Mediation

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Solution Overview

Problem

Aqueous dispersions of water-soluble and water-swellable polymers are unstable due to hydration affinity with the continuous aqueous phase and insufficient suspension of polymer particles, leading to gelling, sedimentation, and creaming issues, which are not effectively addressed by existing stabilizers.

Innovation Solution

An aqueous dispersion comprising particles of water-soluble or water-swellable polymers with a mixture of sulfate and phosphate salts in specific weight proportions (25:75 to 75:25) is used to enhance stability, preventing hydration and improving suspension, thereby reducing sedimentation and creaming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If water-soluble or water-swellable polymers are dispersed in aqueous phase, then the polymer can be used in various applications (flocculation, thickening, water retention), but the dispersion becomes unstable due to hydration affinity leading to gelling and insufficient suspension causing sedimentation and creaming

Engineering Contradiction:
Improveapplication rangeVSAvoiddispersion stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent introduces a specific mixture of inorganic salts (phosphate and sulfate salts) as intermediary substances to mediate between the polymer particles and the aqueous continuous phase. This salt mixture prevents direct harmful hydration of the polymer while maintaining dispersion stability, acting as a protective intermediary that resolves the contradiction between polymer functionality and dispersion stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical composition parameters of the continuous phase by introducing a specific mixture of phosphate and sulfate salts in defined proportions. This parameter change modifies the ionic strength and composition of the aqueous phase, thereby controlling the hydration behavior of polymer particles and preventing both gelling and sedimentation/creaming phenomena.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If polymer particles are suspended in aqueous continuous phase, then the dispersion can function as intended, but insufficient suspension leads to sedimentation and creaming

Engineering Contradiction:
Improvedispersion functionalityVSAvoidsuspension stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The inorganic salt mixture serves as a mediator that improves the interaction between polymer particles and the continuous phase. By adjusting the ionic environment, the salts enhance particle suspension stability without compromising the functional performance of the polymer in applications such as flocculation and thickening.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If polymer hydration is allowed to proceed naturally, then the polymer can perform its function (flocculation, thickening), but excessive hydration causes gelling of the system

Engineering Contradiction:
Improvepolymer functionalityVSAvoidsystem homogeneity
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent modifies the chemical parameters of the continuous phase by introducing phosphate and sulfate salts, which control the hydration equilibrium of the polymer. This parameter adjustment allows the polymer to maintain its functional properties (flocculation, thickening) while preventing excessive hydration that would lead to gelling, thus maintaining system homogeneity.

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 use of a sulfate and phosphate salt mixture significantly increases the stability of the polymer dispersion, allowing a higher incorporation threshold and preventing gelling, resulting in improved long-term stability and reduced sedimentation and creaming.

Implementation Method 1

These are mainly ionic salts or species which prevent deployment of the polymer (1) via screening of the surface charges thereof and (2) via the ionic strength they generate in solution.

Methodology Applied
Scientific EffectIonic strength effect:

Implementation Method 2

These are mainly ionic salts or species which prevent deployment of the polymer (1) via screening of the surface charges thereof and (2) via the ionic strength they generate in solution.

Methodology Applied
Scientific EffectCharge screening:

Implementation Method 3

The other reason results from insufficient suspension of the polymer particles, which in particular is governed by Stokes' law, in the continuous aqueous phase of these dispersions.

Methodology Applied
Scientific EffectStokes' law: Stokes Drift

Implementation Method 4

Water-swellable polymers are able to absorb water up to several hundred times their own weight. They are therefore excellent water retainers.

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 5

The expected and proven benefits of the use of these (co)polymers, via «viscosification» of injected water, are improved sweep and a reduction in viscosity contrast between the fluids

Methodology Applied
Scientific EffectViscosification:

Implementation Method 6

flocculation represents the step at which the particles are grouped together in aggregates of high molecular weight to generate rapid sedimentation

Methodology Applied
Scientific EffectFlocculation: Flocculation

Data Source

PatentUS11702513B2Aqueous dispersion of hydrosoluble or hydroswellable polymer
Publication Date: 2023.07.18 S P C M SA

AI summary

The present invention concerns an aqueous dispersion comprising particles of water-soluble polymer of average molecular weight higher than or equal to 0.5 million daltons, or of water-swellable polymer, and a mixture of at least one sulfate salt and at least one phosphate salt in weight proportions of between 25:75 and 75:25.