Polyarylene Sulfide Monomer Synthesis via Hydrogen Peroxide Oxidation
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Solution Overview
Problem
The conventional preparation of polyarylene sulfide (PAS) monomers involves the use of halogens, which increase production costs and are environmentally unfriendly due to the need for additional purification steps and the formation of byproducts like sulfones and sulfoxides.
Innovation Solution
A method using hydrogen peroxide to selectively oxidize a cationic thioether intermediate, avoiding the formation of sulfones and sulfoxides, and subsequently demethylating the cationic sulfoxide intermediate to produce a polyarylene sulfide monomer without halogens, thereby reducing production costs and environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If halogen (Br2) is used for oxidation of the neutral dithioether compound, then the PPS monomer can be obtained, but the production cost increases and additional purification steps are required
Solution Approach 1:
The patent changes the chemical parameter of the oxidizing agent from halogen (Br2) to hydrogen peroxide (H2O2). This parameter substitution eliminates the need for additional purification steps and reduces production cost while maintaining effective oxidation of the neutral dithioether compound to form the PPS monomer
Solution Approach 2:
The patent replaces expensive halogen-based oxidants with inexpensive hydrogen peroxide. Hydrogen peroxide decomposes into water and oxygen, leaving no harmful residues that require purification, thus eliminating costly waste treatment and purification operations
2Reliability
If halogen (Br2) is used for oxidation, then the PPS monomer can be obtained, but additional purification steps are required which decrease production efficiency
Solution Approach 1:
The patent substitutes the oxidizing agent parameter from halogen to hydrogen peroxide, which fundamentally changes the reaction outcome. Hydrogen peroxide oxidation produces clean products without requiring additional purification steps, thereby streamlining the production process and increasing overall productivity
Solution Approach 2:
The patent extracts and eliminates the problematic purification steps from the production process by using hydrogen peroxide instead of halogen. The reaction with hydrogen peroxide is so clean that it removes the need for separate purification operations, directly improving production efficiency
3Reliability
If halogen is used for oxidation, then the PPS monomer can be obtained, but environmental harm increases due to halogen waste
Solution Approach 1:
The patent changes the chemical composition parameter of the oxidizing agent from halogen to hydrogen peroxide. This substitution transforms the waste products from harmful halogen compounds to benign water and oxygen, completely eliminating environmental harm while maintaining effective oxidation
Solution Approach 2:
The patent converts potentially harmful halogen-based oxidation into environmentally benign hydrogen peroxide oxidation. The decomposition products of hydrogen peroxide (water and oxygen) are beneficial or neutral, transforming what would have been a harmful process into an environmentally friendly one
4Manufacturing precision
If conventional purification steps are added to remove halogen byproducts, then the PAS resin quality can be improved, but the production cost increases
Solution Approach 1:
The patent applies preliminary anti-action by preventing the formation of harmful halogen byproducts in the first place through using hydrogen peroxide as the oxidizing agent. This proactive approach eliminates the need for subsequent purification steps to remove contaminants, maintaining high PAS resin quality without additional cost
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 effectively prepares polyarylene sulfide monomers with improved efficiency and reduced environmental impact by eliminating the need for halogen-based oxidation, thus lowering production costs and enhancing the quality of the PAS resin.
Implementation Method 1
reacting hydrogen peroxide with (i) a compound having the following formula (2) or sulfonic acid R'SO3H and (ii) a cationic thioether intermediate having the following formula (4) to obtain the cationic sulfoxide intermediate
Data Source
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AI summary
A method for preparing a cationic sulfoxide intermediate having the following formula (1): wherein Ar1 and Ar2 are substituted or unsubstituted aryl groups that are the same or different, includes reacting hydrogen peroxide with (i) a compound having the following formula (2) or sulfonic acid R'SO3H, wherein R' is CH3, CF3, phenyl, toluene, or OH, and (ii) a cationic thioether intermediate having the following formula (4) to obtain the cationic sulfoxide intermediate: wherein R is a substituted or unsubstituted C1-C6 alkyl group; and wherein Ar1 and Ar2 are as defined above and Y is an anion.