Perfluoro Surfactant Synthesis via Micro-Channel Ozonation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluorosurfactants with non-fluorine atom chemical bonds are unstable under high temperature and high-pressure conditions in fluoropolymer emulsion polymerization, leading to low average molecular weight of fluoropolymers, increased initiator consumption, and instability of fluoropolymer emulsions, which can result in production accidents.
Innovation Solution
A perfluoro surfactant with a specific molecular structure (formula I) that avoids non-fluorocarbon-halogen bonds, combined with a continuous micro-channel reaction system for ozonation and photo-oxidation, ensuring the stability of carbon-fluorine bonds and reducing side reactions, thereby increasing the average molecular weight of fluoropolymers and improving emulsion stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fluorosurfactants with non-fluorine atom chemical bonds are used, then the surfactant can be synthesized with lower complexity, but the chemical bonds are easily broken under high temperature and high-pressure conditions resulting in low average molecular weight of fluoropolymers
Solution Approach 1:
The patent changes the chemical composition parameter of the surfactant from containing non-fluorine bonds to containing only carbon-fluorine bonds. This parameter change ensures that the surfactant maintains high bond stability under high temperature and pressure conditions, preventing bond breakage and free radical formation that would otherwise reduce polymer molecular weight.
Solution Approach 2:
The patent employs a composite molecular structure where the surfactant contains both hydrophilic and hydrophobic segments, with the critical innovation being that all carbon-halogen bonds are carbon-fluorine bonds. This composite structure with uniform high-strength bonding provides both the necessary surfactant functionality and the thermal stability required for high-performance fluoropolymer production.
2Productivity
If non-fluorine atom bonds in fluorosurfactants break under high temperature and high-pressure conditions, then free radicals are formed, but this results in decreased average molecular weight of fluoropolymer and increased initiator consumption
Solution Approach 1:
The patent applies prior cushioning by designing a surfactant with inherently stable carbon-fluorine bonds that resist breakage under polymerization conditions. This preventive design eliminates the need for continuous initiator addition to compensate for bond breakage, thereby reducing initiator consumption and maintaining high polymer production efficiency.
3Reliability
If non-fluorine atom bonds break in fluorosurfactants, then free radicals are formed, but this causes instability of fluoropolymer emulsions and potential production accidents
Solution Approach 1:
The patent changes the chemical bond composition parameter from including non-fluorine bonds to exclusively carbon-fluorine bonds. This parameter change eliminates the source of free radical generation, thereby maintaining emulsion stability under high temperature and pressure conditions and preventing demulsification and production accidents.
4Ease of manufacture
If perfluorooctanoic acid with 8-carbon linear structure is used in fluorosurfactants, then the surfactant can be easily synthesized, but it is biologically toxic, carcinogenic, and easily enriched in the natural environment
Solution Approach 1:
The patent changes the molecular structure parameter by eliminating the 8-carbon linear perfluorooctanoic acid structure. Instead, it employs a surfactant structure where all carbon-halogen bonds are carbon-fluorine bonds, achieving both ease of manufacture through established fluorination chemistry and elimination of the harmful 8-carbon structure that causes toxicity and environmental persistence.
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 perfluoro surfactant significantly increases the average molecular weight of fluoropolymers, reduces the need for continuous initiator addition, enhances the stability of fluoropolymer emulsions, and improves production safety by maintaining the integrity of carbon-fluorine bonds and minimizing side reactions.
Implementation Method 1
ozonation: continuously pass hexafluoropropylene and ozone into the reaction system to obtain the active intermediate of formula II
Implementation Method 2
photo-oxidation: pass hexafluoropropylene and oxygen into the reactive intermediate of formula II to obtain perfluoropolyether acyl fluoride of formula III
Implementation Method 3
hydrolysis: pour deionized water into the perfluoropolyether acyl fluoride of formula III, and obtain the perfluoro surfactant of formula I after hydrolysis
Data Source
AI summary
A perfluoro surfactant and a preparation method therefor. A carbon fluorine bond is not prone to break when the perfluoro surfactant is used as an emulsifier in a fluorine polymer reaction, such that the average molecular weight of a fluorine polymer generated in the fluorine polymer reaction is significantly increased. The preparation method is implemented in a continuous micro-channel reaction system, where the retention time of a reactant in the reaction system can be greatly shortened to few minutes or even seconds, a back-mixing phenomenon in the reaction system can be basically eliminated, and thus the occurrence of a side reaction, an optical coupling reaction, can be greatly reduced. There are reaction stages comprising an ozonization reaction and a photo-oxidation reaction.