Sulfur-Containing Macromolecules for High Refractive Index
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Solution Overview
Problem
Current methods for synthesizing sulfur-containing macromolecules face challenges such as reactivity, solubility issues, and complexity in monomer synthesis, particularly in achieving high refractive index and transparency while maintaining processability and thermal stability.
Innovation Solution
A new method involving the hydrothiolation of alkynes with thiols to produce sulfur-containing polymers using a one-pot single-step reaction, catalyzed by either basic conditions or transition-metal catalysts, resulting in high yields and molecular weights, and allowing for easy film formation and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If sulfur moieties are incorporated into macromolecular structure to obtain high refractive index, then refractive index is improved, but reactivity and solubility deteriorate
Solution Approach 1:
The patent introduces long alkyl chains (such as hexyl groups) at specific positions on the sulfur-containing macromolecule structure. These alkyl chains are localized substituents that provide solubility and processability without affecting the core sulfur-containing units that give high refractive index. This local modification resolves the contradiction between high refractive index and solubility.
Solution Approach 2:
The patent creates composite macromolecular structures combining sulfur-containing rigid units (for high refractive index) with flexible alkyl chain segments (for solubility and processability). This composite approach allows the material to simultaneously achieve high optical performance and good processing characteristics.
2Stability of the object's composition
If conventional methods are used to synthesize sulfur-containing macromolecules, then sulfur incorporation is achieved, but synthesis complexity and difficulty increase
Solution Approach 1:
The patent combines multiple synthetic steps into a one-pot reaction where the sulfur-containing macromolecule is synthesized directly from readily available starting materials. The reaction sequence integrates monomer formation, polymerization, and purification steps into a single operational procedure, dramatically reducing synthesis complexity while maintaining high sulfur incorporation.
Solution Approach 2:
The patent uses readily available starting materials that are pre-functionalized with necessary groups for the final structure. By preparing monomers with appropriate protecting groups and functional handles in advance, the actual polymerization and sulfur incorporation steps are simplified and can be performed under mild conditions.
3Productivity
If metal catalysts are used for hydrothiolation, then reaction efficiency is improved, but product yield decreases due to poisonous interactions
Solution Approach 1:
The patent employs organic base catalysts (such as triethylamine or diisopropylethylamine) as intermediaries to facilitate the hydrothiolation reaction between alkynes and thiols. These base catalysts activate the thiol groups without suffering from the poisonous interactions that plague metal catalysts, thereby maintaining high reaction efficiency while avoiding catalyst deactivation and achieving high product yields.
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 sulfur-containing polymers with high refractive indices, high transparency, and improved processability, facilitating their application in photo-optical devices and other materials requiring these properties.
Implementation Method 1
In 1956, Truce and Simms discovered a nucleophilic reaction between aromatic or alkyl acetylene with sodium thiolate, which gives vinyl sulfides in high yields
Implementation Method 2
The polymerization reaction can be catalyzed by either basic conditions or a transition-metal catalyst
Data Source
AI summary
A sulfur-containing macromolecule and a method of preparing the sulfur-containing macromolecule comprising a polymerization step are provided, where the sulfur-containing macromolecule contains internal units of formula (I) and the polymerization step is formula (II) wherein n is greater than 1, said precursor comprises alkyne having one or more acetylene groups and thiol having one or more thiol groups; and R is remainder of said thiol excluding said thiol groups, R′ is remainder of said alkyne excluding said acetylene groups, and R and R′ are selected from organic or organometallic groups.