Porous Polymer Composites via Sacrificial Poragen Extraction
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Solution Overview
Problem
Current methods for producing porous polymer composites face limitations in achieving high porosity, surface area, and mass transport due to issues with foaming agents, phase separation, and particulate loading, which hinder their effectiveness in applications such as hemorrhage control, where deep and complex wounds require materials that can conform, penetrate, and control bleeding effectively.
Innovation Solution
A method of forming porous particulate-loaded polymer composites by mixing a polymer with a solvent and a particulate filler below the mechanical percolation threshold, then removing the solvent to concentrate the polymer and filler, creating a porous structure with increased particulate loading above the threshold, and optionally removing some filler to maintain a particulate-loaded inner core and unfilled outer shell, enhancing porosity and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of stationary object
If foaming agents are used to produce porosity, then density is decreased, but mass transport through the material is eliminated due to closed cell structure
Solution Approach 1:
The patent extracts the harmful effect of closed-cell encapsulation by using a sacrificial poragen that is completely removed after processing. The poragen creates void spaces during processing but is subsequently extracted, leaving open-cell porosity that enables mass transport while maintaining low density.
Solution Approach 2:
The patent employs a sacrificial poragen material that temporarily occupies space during processing, then is removed to create permanent porous structures. This approach generates open-cell foam morphology with interconnected pores that facilitate both low density and effective mass transport.
2Quantity of substance
If high poragen loading is used to obtain interconnected pores, then porosity and surface area are increased, but viscosity increases exponentially making processing difficult
Solution Approach 1:
The patent changes the physical state parameters of the poragen from solid particles to liquid or low-melting-point material that can be easily incorporated at high loadings without significantly increasing viscosity. After processing, the poragen is removed through extraction or melting, leaving the desired porous structure.
3Quantity of substance
If particulate filler is incorporated to produce porosity, then porosity is increased, but the particulate eliminates multi-functional benefits and can alter phase separation kinetics
Solution Approach 1:
The patent removes the particulate filler completely after it has served its purpose as a poragen during processing. This extraction eliminates any potential negative effects on multi-functionality or phase separation kinetics in the final product, while still achieving the desired porous structure.
Solution Approach 2:
The particulate filler is used as a temporary, disposable element during processing that is completely removed afterward. It serves only to create porosity during manufacturing and has no role in the final product's functionality, avoiding interference with the material's intended multi-functional performance.
4Manufacturing precision
If block copolymers are used for phase separation, then porosity is achieved with controlled length scale, but phase separation kinetics are slow limiting practical implementation
Solution Approach 1:
The patent introduces a sacrificial poragen as an intermediary material that temporarily controls pore formation during processing. This poragen can be easily removed after processing, leaving the desired porous structure without being constrained by slow phase separation kinetics of block copolymers.
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 approach allows for the creation of porous polymer composites with interconnected structures that can effectively manage hemorrhage by conforming to complex wounds, controlling bleeding, and maintaining mechanical robustness, while being cost-effective and easily applied.
Implementation Method 1
removing the solvent from the first polymer composition to concentrate the first polymer and particulate filler
Implementation Method 2
removing the solvent from the first polymer composition to concentrate the first polymer and particulate filler
Implementation Method 3
Porosity has also been incorporated into a polymer matrix through phase separation of the formulation. In these systems, the components have limited miscibility resulting in the constituents segregating into discrete regions prior to cure
Data Source
AI summary
Porous polymer composites and methods of preparing porous polymer composites are provided herein. In some embodiments, a method for preparing porous polymer composites may include mixing a first polymer with a solvent and a particulate filler to form a first polymer composition, wherein the amount of particulate filler in the first polymer composition is below a mechanical percolation threshold; and removing the solvent from the first polymer composition to concentrate the first polymer and particulate filler into a second polymer composition having a porous structure, wherein the particulate filler concentration in the second polymer composition is increased above the mechanical percolation threshold during solvent removal.