Polymer Composite High Solids Dispersion via Supercritical Extraction
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Solution Overview
Problem
Conventional methods face challenges in achieving uniform dispersion and high concentration of inorganic particles or fibrous materials, such as nanocellulose, within polymer matrices, particularly due to hydrophilic nature and high water content, limiting solids content in aqueous slurries and polymer composites.
Innovation Solution
A method involving a mixture of a liquid, polymer precursor, and dispersed-phase precursor subjected to specific reaction conditions of pressure between 10 millitorr and 300 torr and temperature greater than the boiling point of the liquid but below the decomposition temperatures of the polymer and dispersed-phase precursor, facilitating polymerization and removal of the liquid, resulting in a well-dispersed composite material that can be treated with cross-linking agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional mixing methods (simple mixing, high shear mixing, dispersants) are used to disperse inorganic particles or nanocellulose in polymer matrix, then the process is simple and easy to operate, but the dispersion uniformity is poor and solids content is limited (cannot achieve greater than 3% nanocellulose solids in water-based slurry or greater than 70-72% inorganic solids in aqueous slurry)
Solution Approach 1:
The patent changes the physical and chemical parameters of the system by using a two-stage process: first forming a slurry with controlled water content and pH, then applying supercritical carbon dioxide extraction. This transforms the dispersion mechanism from conventional mechanical mixing to a supercritical fluid-based process, enabling high solids content (greater than 3% nanocellulose, greater than 70-72% inorganic materials) while maintaining uniform dispersion. The supercritical CO2 acts as an extraction medium that removes water and facilitates uniform distribution of dispersed phase particles throughout the polymer matrix.
Solution Approach 2:
The patent utilizes the phase transition properties of carbon dioxide between supercritical and gaseous states. By heating and pressurizing CO2 to supercritical conditions during extraction, then allowing it to return to gaseous state, the system achieves efficient water removal and dispersed phase distribution. The phase change enables the CO2 to penetrate the slurry matrix effectively, extract water, and then expand upon pressure release to maintain uniform dispersion of high concentrations of nanocellulose or inorganic particles without aggregation.
2Ease of operation
If high water content slurry is used to disperse nanocellulose, then the slurry can flow and be pumped, but the solids content is limited (cannot achieve greater than 3% solids content)
Solution Approach 1:
The patent applies preliminary action by first preparing a slurry with adequate water content to ensure pumpability and proper dispersion of nanocellulose particles before the extraction step. The slurry is formulated with appropriate pH and water content to achieve uniform initial distribution. Only after this preliminary dispersion step is complete does the supercritical CO2 extraction begin to remove water and concentrate the solids. This sequence allows the system to benefit from the flow properties of water-based slurry during preparation, then achieve high solids content during the extraction phase without compromising initial pumpability.
Solution Approach 2:
The patent uses the phase transition of water from liquid to vapor through supercritical CO2 extraction. The supercritical CO2 selectively extracts water from the slurry, transforming it from a water-based mobile system to a dry, high-solids composite. This phase removal mechanism enables the system to start with pumpable slurry (high water content) and end with high solids content material, as the water is systematically removed through the supercritical extraction process rather than being present during the final composite formation.
3Quantity of substance
If high solids content of inorganic materials (greater than 70-72%) is achieved in aqueous slurry, then the concentration is improved, but the slurry becomes difficult to pump and process
Solution Approach 1:
The patent applies preliminary action by preparing the slurry at lower solids content with adequate water to ensure pumpability during the preparation and loading phase. The inorganic materials are dispersed in water at concentrations that maintain fluidity and pumpability. Only after the slurry is properly formed and loaded into the processing system does the supercritical CO2 extraction begin to remove water and increase the effective solids content to greater than 70-72%. This preliminary formulation approach allows high final solids content to be achieved without the intermediate step of handling pumpable high-concentration slurries.
Solution Approach 2:
The patent uses supercritical CO2 extraction to induce a phase transition that removes water from the slurry system. By transforming the extraction medium to supercritical state and then allowing it to return to gaseous state, the process systematically removes water while maintaining inorganic particle suspension. This enables the system to achieve high inorganic solids content (greater than 70-72%) in the final composite without requiring the intermediate handling of high-concentration slurries, as the water removal occurs in situ during the extraction process rather than requiring pre-preparation of pumpable high-solids slurries.
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 method enables the production of composite materials with higher dispersed phase concentrations and improved dispersion, allowing for enhanced compatibility and properties in applications like paper coatings and plastics, with improved solvent resistance and reduced binder migration.
Implementation Method 1
subjecting the mixture to reaction conditions sufficient: (i) to effect polymerization of the polymer precursor to produce a polymer
Implementation Method 2
remove substantially all the liquid and reaction product from the mixture; wherein said reaction conditions comprise: (a) pressure between about 10 millitorr and about 300 torr; and (b) temperature: (i) greater than or equal to the highest boiling point of the liquid and reaction product
Implementation Method 3
pressure between about 10 millitorr and about 300 torr; temperature: greater than or equal to the highest boiling point of the liquid and reaction product
Data Source
AI summary
Disclosed are processes for making polymeric composite materials and composite materials made from those processes, the process comprising: providing a mixture, comprising: a liquid, a polymer precursor, and a dispersed-phase precursor; and subjecting the mixture to reaction conditions sufficient: to effect polymerization of the polymer precursor to produce a polymer and a reaction product; and to remove substantially all the liquid and reaction product from the mixture; wherein said reaction conditions comprise: pressure between about 10 millitorr and about 300 torr; and temperature: greater than or equal to the highest boiling point of the liquid and reaction product; less than the decomposition temperature of the polymer; and less than the decomposition temperature of the dispersed-phase precursor.