Arylaminosilane External Electron Donor for Propylene Polymerization
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Solution Overview
Problem
Current propylene polymerization catalysts often result in polypropylene with low isotacticity when no external electron donor is used, which is disadvantageous for industrial production, and while organosiloxane external electron donors improve isotacticity, there is a lack of reports on arylaminosilane compounds in this context.
Innovation Solution
The development and use of arylaminosilane compounds as external electron donors in propylene polymerization, specifically compounds like (N-methylanilino)trimethoxysilane and (2,6-diisopropyl-N-trimethylsilylanilino)trimethoxysilane, which are synthesized through reactions with alkyl lithium and silicon chlorides, and their incorporation into a propylene polymerization catalyst system with a solid titanium catalyst and alkyl aluminum compound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If no external electron donor is added to the propylene polymerization catalyst, then the catalyst system is simpler, but the isotacticity of the polypropylene product is low (generally lower than 90%)
Solution Approach 1:
The patent changes the chemical structure parameters of the external electron donor from conventional organosiloxane to arylaminosilane compound. This structural parameter change results in improved isotacticity (达到95%以上) while maintaining reasonable catalyst system complexity, resolving the contradiction between simplicity and performance.
Solution Approach 2:
The patent creates a composite catalyst system combining solid titanium catalyst, alkyl aluminum co-catalyst, and arylaminosilane external electron donor. This composite approach synergistically improves isotacticity to above 95% while managing the overall system complexity through optimized component interactions.
2Manufacturing precision
If conventional organosiloxane external electron donors are used, then the isotacticity of polypropylene is improved, but there is a lack of reports on arylaminosilane compounds indicating unexplored potential
Solution Approach 1:
The patent expands the versatility of electron donor types by introducing arylaminosilane compounds with general formula (I), where R1-R9 can vary within specific ranges. This parameter variation approach creates a family of compounds with different isotacticity-enhancing capabilities, broadening the available options beyond conventional organosiloxane.
Solution Approach 2:
The patent applies local quality by designing specific substituent groups (R1-R9) at different positions of the arylaminosilane structure. Different substituent combinations provide locally optimized electron donor properties, enabling fine-tuning of isotacticity enhancement while exploring new chemical space.
3Manufacturing precision
If arylaminosilane compounds are used as external electron donors, then the isotacticity and melt index of polypropylene are enhanced, but the synthesis requires multiple reaction steps with alkyl lithium and silicon chlorides
Solution Approach 1:
The patent applies preliminary action by pre-synthesizing the arylaminosilane compounds with controlled substituent patterns before polymerization. This advance preparation allows optimization of the electron donor structure-isotacticity relationship, achieving above 95% isotacticity and improved melt index despite the multi-step synthesis requirement.
Solution Approach 2:
The patent systematically varies parameters R1-R9 in the arylaminosilane structure to optimize the balance between synthesis complexity and polymerization performance. By changing substituent types and positions, the patent achieves high isotacticity (above 95%) and enhanced melt index while managing synthetic complexity through rational molecular design.
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 arylaminosilane compounds enhance the isotacticity and melt index of polypropylene, offering a high flowability and high isotacticity, thus improving the polymerization process and product quality.
Implementation Method 1
Solid catalyst with magnesium, titanium, halogen and electron donor as basic components can be used in CH2═CHR propylene polymerization reaction
Data Source
AI summary
The present disclosure discloses an arylaminosilane compound, a propylene polymerization catalyst and preparation thereof. The arylaminosilane compound has a structure ofwherein R1 is a C1-C8 alkyl group or a C1-C8 silanyl group; R2, R3, R4, R5 and R6 are each independently H or a C1-C12 alkyl group; R7, R8 and R9 are each independently a C1-C8 alkyl group or a C1-C8 alkoxy group. When the arylaminosilane compound is used as an external electron donor of a propylene polymerization catalyst in propylene polymerization reaction, the catalyst has good hydrogen response.