Fluoroolefin Aqueous Dispersion for High Conversion Polymerization
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Solution Overview
Problem
Conventional methods for producing sulfonic acid-type functional group-containing fluoroolefin copolymers face issues such as increased viscosity, difficulty in achieving high conversion rates, corrosion of equipment, and environmental concerns due to the use of harsh chemicals and solvents, leading to problems like bubbling and delamination during film formation and membrane lamination.
Innovation Solution
An aqueous dispersion with a specific composition and physical properties, including a fluoroolefin and surfactant, is developed to stabilize the terminal structure of low-molecular compounds and control the content of these compounds within the copolymer, preventing bubbling and delamination, and using environmentally friendly components to reduce environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional polymerization methods are used to produce sulfonic acid-type functional group-containing fluoroolefin copolymers, then the polymer can be obtained, but the viscosity of the system rapidly increases and high conversion rate is difficult to achieve
Solution Approach 1:
The invention changes the chemical structure parameters of the copolymer by incorporating fluorinated side chains with specific lengths and configurations. This structural modification reduces intermolecular interactions and maintains lower viscosity while enabling higher conversion rates during polymerization
Solution Approach 2:
The invention creates a composite copolymer structure combining fluoroolefin backbone with sulfonic acid functional groups and fluorinated side chains. This composite structure achieves both high conversion rate and manageable viscosity through balanced molecular architecture
2Reliability
If sulfonic acid-type functional group-containing perfluorocarbon copolymer is used for cation exchange membrane, then high current efficiency and low electrolytic voltage are achieved, but the functional group is easily hydrolyzed reducing melt-moldability
Solution Approach 1:
The invention introduces fluorinated hydrocarbon chains as intermediary structures between the sulfonic acid functional groups and the polymer backbone. These intermediary fluorinated chains act as protective barriers that reduce hydrolysis of the sulfonic acid groups while maintaining the necessary ion exchange functionality
Solution Approach 2:
The invention modifies the chemical environment of the sulfonic acid groups by incorporating electron-withdrawing fluorinated side chains. This changes the electronic parameters and steric protection around the functional groups, reducing their susceptibility to hydrolysis while preserving melt-moldability
3Productivity
If conventional copolymerization methods are used, then copolymer can be produced, but low polymers (oligomers) remain in the polymer requiring additional washing steps
Solution Approach 1:
The invention changes the polymerization parameters and copolymer composition to favor formation of high molecular weight chains. By adjusting the monomer ratio and incorporating specific fluorinated monomers, the reaction kinetics are modified to reduce oligomer formation and improve polymerization efficiency
4Ease of manufacture
If C8F17COONH4 is used as emulsifier, then polymerization can proceed, but environmental concerns arise due to use of harsh chemicals
Solution Approach 1:
The invention replaces persistent environmental contaminants like C8F17COONH4 with biodegradable alternative emulsifiers. These short-living, environmentally benign emulsifiers perform the necessary polymerization function but decompose harmlessly, eliminating long-term environmental accumulation
Solution Approach 2:
The invention converts the potential harm of using emulsifiers by selecting biodegradable options that provide the same polymerization processability benefits while offering environmental benefits. The emulsification function is maintained but the environmental footprint is transformed from harmful to beneficial
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 solution enables high conversion ratios and productivity of copolymers without corroding vessels, effectively suppressing bubbling and delamination during film formation and membrane preparation, while being environmentally friendly.
Implementation Method 1
an aqueous dispersion comprising: a fluoroolefin (a)... a surfactant (c)... wherein the aqueous dispersion has a cumulant diameter of 250 to 2,000 nm
Implementation Method 2
Examples of the method for polymerizing such a fluorine-containing copolymer include an emulsion polymerization method
Data Source
AI summary
[Problem to be Solved]Provided are an aqueous dispersion of a fluoroolefin and the like that do not corrode vessels and enable a copolymer to be given at a high conversion ratio and high productivity from the fluoroolefin as a raw material monomer.[Solution]An aqueous dispersion containing:a fluoroolefin (a) represented by the following general formula (1);a surfactant (c) represented by the following general formula (2); anda dispersion medium containing water,wherein the aqueous dispersion has a cumulant diameter of 250 to 2,000 nm, andthe aqueous dispersion has a pH of 2.0 to 7.0:CF2═CF—[O—CF2—CF(CF3)]n—O—[CF2]m—Z (1)wherein n represents an integer of 0 or more and 2 or less, m represents an integer of 2 or more and 4 or less, and Z represents CF3, SO2F, or COOH3, andCF3—[CF2]m—O—[CF(CF3)—CF2—O]n—CF(CF3)—Z (2)wherein m represents an integer of 0 to 2, n represents an integer of 0 to 6, Z represents COOM, wherein N represents H, Li, Na, K, or NR4, wherein R represents H or a linear alkyl group having 1 to 4 carbon atoms.