DCPD Metathesis Catalyst Ligand Design for Solubility
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Solution Overview
Problem
The existing catalysts for dicyclopentadiene metathesis polymerization face challenges such as high catalyst consumption, low yield, and impaired polymer quality due to poor solubility and microcapsule formation, leading to increased production costs and suboptimal polydicyclopentadiene properties.
Innovation Solution
Development of new catalysts with improved solubility and synthesis methods, specifically using second-generation Grubbs catalysts and indenylidene complexes, which are prepared through interactions with specific amines and phosphines in inert atmospheres at controlled temperatures, allowing for higher yields and better monomer-to-catalyst ratios, up to 200,000:1, and enabling efficient dicyclopentadiene metathesis polymerization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If second-generation Grubbs catalysts are used for DCPD metathesis polymerization, then catalytic activity is improved, but catalyst consumption increases due to poor solubility and microcapsule formation
Solution Approach 1:
The patent modifies the catalyst structure by changing ligands from traditional phosphines to N-heterocyclic carbenes (NHCs), which fundamentally alters the catalyst's solubility parameters and steric properties. This structural parameter change enables the catalyst to remain soluble in the monomer phase without forming microcapsules, thereby maintaining high catalytic activity while reducing catalyst consumption through the improved monomer-to-catalyst ratio capability
Solution Approach 2:
The invention creates a composite catalyst system combining ruthenium center with N-heterocyclic carbene ligands and specific phosphine or NHC ligands (Formula I and II). This composite structure integrates the high activity of Ru-based catalysts with the enhanced solubility and stability of NHC ligands, resolving the contradiction between catalytic power and catalyst consumption
2Stability of the object's composition
If catalyst is pre-dissolved in inert solvent to improve solubility, then catalyst dispersion is improved, but polymer quality is impaired
Solution Approach 1:
The patent extracts and eliminates the need for inert solvents by designing a catalyst system that is inherently soluble in the monomer. The NHC-based catalysts can be directly dissolved in DCPD without requiring separate solvent dissolution steps, thereby removing the source of polymer quality impairment while maintaining excellent catalyst solubility and dispersion
Solution Approach 2:
The N-heterocyclic carbene ligands act as intermediaries that bridge the catalyst and monomer, enabling direct solubilization of the catalyst in the monomer phase. This intermediary structure allows the catalyst to interact effectively with DCPD without requiring inert solvent mediation, thus preserving polymer quality
3Manufacturing precision
If multi-stage synthesis method is used to prepare catalyst, then catalyst structure is well-defined, but synthesis yield is low (50-65%)
Solution Approach 1:
The patent employs preliminary action by pre-synthesizing and characterizing the N-heterocyclic carbene ligands and indenylidene complexes before final catalyst assembly. This preparatory work ensures that the multi-stage synthesis proceeds with high efficiency and minimal side reactions, improving overall yield while maintaining structural precision
Solution Approach 2:
The synthesis is segmented into distinct modular stages: indenylidene complex preparation, NHC ligand synthesis, and final catalyst assembly. Each segment is optimized independently with specific conditions (temperature, solvent, atmosphere), allowing high yield in each step while maintaining the overall well-defined structure of the final catalyst product
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 new catalysts significantly reduce catalyst consumption, enhance polymer yield to 75-90%, and improve polydicyclopentadiene properties, achieving higher monomer-to-catalyst ratios and better solubility, resulting in cost-effective and high-quality polydicyclopentadiene production with enhanced mechanical and thermal properties.
Implementation Method 1
Second generation Grubbs catalyst (GII) is subject to interaction with N,N-di-alkyl-(2-vinyl-benzyl)amine or 1-(2-vinyl-benzyl)pyrrolidine or 4-(2-vinyl-benzyl)morpholine in inert atmosphere at temperatures of 60-85 °C
Implementation Method 2
indenylidene complex of ruthenium is isolated and then in one reactor it is step by step subject to interaction with 1,3-bis-(2,4,6-trimethylphenyl)-2-tri-chloro-methyl-imidazolidine and 2-(N,N-dialkyl-aminomethyl)styrene or 1-(2- vinyl-benzyl)pyrrolidine or 4-(2- vinyl-benzyl)morpholine in toluene with heating at 60-70°C
Implementation Method 3
allowing preparing polydicyclopentadiene with high application properties at monomer : catalyst mole ratio 70000:1 to 200000:1, whereas for the known catalysts this ratio is 30000: 1 and 40000:1
Implementation Method 4
catalyst for dicyclopentadiene metathesis polymerization
Data Source
AI summary
This invention relates catalysis and concerns production of catalyst for dicyclopentadiene (DCPD) ring-opening metathesis polymerization. Catalyst for metathesis polymerization has the formula: where L is a substituent selected from the group: Several methods of the catalyst preparation were developed: Method of preparing catalyst having the following formula where L where the second generation Grubbs catalyst is subject to interaction with (N,N-dialkyl-(2-vinylbenzyl)amine or 1-(2- vinylbenzyl)pyrrolidine or 4-(2- vinylbenzyl)morpholine in inert atmosphere at temperatures of 60-85 °C in the presence of a solvent, with dialkyl- being methylethyl- or methyl(2-metoxyethyl). Method of preparing catalyst having the following formula where L is a substituent selected from the group: where triphenylphosphine complex of ruthenium is subject to interaction with 1,1-diphenyl-2-propyne-1-ol in tetrahydrofuran at the temperature of solvent boiling in inert atmosphere, and then with tricyclohexylphosphine at room temperature in inert atmosphere; indenylidene complex of ruthenium formed is recovered and then step by step, in one reactor, it is subject to interaction with 1,3-Bis(2,4,6-trimethylphenyl)-2-(trichloromethyl)imidazolidine and 2-(N,N-dialkylaminomethyl)styrene or 1-(2-vinylbenzyl) pyrrolidine HJIH 4-(2- vinylbenzyl)morpholine in toluene with heating at 60-70°C in inert atmosphere, with dialkyl- being dimethyl, diethyl-, or methylethyl- or methyl(2-metoxyethyl)-. Method of metathesis polymerization of dicyclopentadiene has been also developed where polymerization is carried out with the catalyst of item 1 with mole ratio of substrate to catalyst of 70000:1 to 200000:1. Invention allows increasing of the catalyst yield and simplifies schemes of synthesis through reducing number of stages, as well as preparing polydicyclopentadiene with high application properties.