Polyimide Micronized Particles via High-Shear Emulsion Control
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Solution Overview
Problem
Existing methods for producing polyimide particles with specified size parameters are inefficient and unsuitable for commercial production, particularly in achieving small particle sizes with spherical morphology.
Innovation Solution
A method involving combining a polyimide solution with an aqueous solution in the presence of an emulsifying surfactant under high shear agitation, followed by solvent removal and recovery of polyimide particles through centrifugation or pressure filtration, achieving polyimide particles with defined size distributions and spherical morphology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If conventional methods are used to make small polyimide particles, then particle size can be reduced, but production rate is low and efficiency is poor
Solution Approach 1:
The invention changes the physical and chemical parameters of the system by using specific organic solvents (methylene chloride, chloroform, or a mixture) with controlled concentrations (1-30 wt% polyimide solution), and optimizing emulsification parameters (surfactant concentration at 0.1-5 wt%, agitation speed at 1,500-2,500 rpm) to achieve both small particle size and high production rate simultaneously
Solution Approach 2:
The invention introduces an emulsifying surfactant as an intermediary substance that facilitates the formation of stable emulsion between polyimide solution and water, enabling efficient mass transfer and particle formation. The surfactant acts as a mediator that allows the system to produce small spherical particles at high rates by stabilizing the emulsion interface during rapid mixing
2Manufacturing precision
If high shear agitation is used to form emulsion, then particle size distribution is improved, but energy consumption increases
Solution Approach 1:
The invention applies high shear agitation at specific rotational speeds (1,500-2,500 rpm) which is sufficient to achieve the desired particle size distribution (D10: 3-50 μm, D90: 3-80 μm, D100: 3-100 μm) without excessive energy input. This optimized range provides the necessary mixing intensity for precise particle size control while avoiding energy waste from overly aggressive mixing conditions
3Shape
If surfactant concentration is increased to improve emulsion stability, then particle morphology is enhanced, but residual surfactant in particles increases
Solution Approach 1:
The invention optimizes the surfactant concentration parameter within a specific range (0.1-5 wt% of total composition) to achieve the desired spherical morphology while controlling residual surfactant levels. By carefully adjusting this parameter and optimizing the emulsification process, the method produces particles with excellent spherical shape and controlled surface properties while minimizing harmful residues
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 method enables the production of polyimide particles with controlled size parameters and high recovery rates, reducing the formation of small particles and achieving bulk densities greater than 0.5 g/cm³, with low surfactant and solvent concentrations.
Implementation Method 1
combining a polyimide solution including a polyimide and an organic solvent with an aqueous solution comprising water in the presence of an emulsifying surfactant using high shear agitation
Implementation Method 2
combining a polyimide solution including a polyimide and an organic solvent with an aqueous solution comprising water in the presence of an emulsifying surfactant using high shear agitation at a rotational speed from 1,500 to less than 2,500 revolutions per minute to form an emulsion
Implementation Method 3
removing the organic solvent from the emulsion to form an aqueous polymer dispersion comprising polyimide particles
Implementation Method 4
recovering the polyimide particles from the aqueous polymer dispersion
Data Source
Figure 1~2
Figure 3
AI summary
A method of manufacturing polyimide particles, including: combining a polyimide solution including a polyimide and an organic solvent with an aqueous solution including water in the presence of an emulsifying surfactant at a shear rate from 1,000 to 3,000 revolutions per minute, from 1,000 to 2,500 revolutions per minute, or from 1,500 to less than 2,500 revolutions per minute to form an emulsion; removing the organic solvent to form an aqueous polymer dispersion including polyimide particles; and recovering the polyimide particles, which have a spherical morphology, and a volume based D10 diameter from 3 to 50 micrometers, preferably from 3 to 45 micrometers and a volume based D90 diameter from 3 to 80 micrometers, from 3 to 75 micrometers, or from 3 to 45 micrometers and a volume based D100 diameter from 3 to 100 micrometers, from 3 to 75 micrometers, or from 10 to 75 micrometers.