Aromatic 1,4-diether Catalyst for Olefin Polymerization Activity
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Solution Overview
Problem
Current Ziegler-Natta catalyst systems for olefin polymerization have limitations in catalyst activity, isotacticity, and molecular weight distribution, restricting the application of polyolefins due to the relatively narrow molecular weight distribution and low activity of existing electron donors.
Innovation Solution
Development of novel internal electron donors, specifically aromatic 1,4-diethers, which are used in combination with organic acid esters and 1,3-diethers to enhance catalyst activity and adjust isotacticity and molecular weight distribution of poly-alpha-olefins, allowing for a more controllable and efficient olefin polymerization and copolymerization process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing electron donors (monobasic acid esters, dibasic acid esters, succinate, maleate, glutarate) are used in Ziegler-Natta catalyst system, then catalyst activity is improved to certain degree, but the enhancement is not obvious and molecular weight distribution remains narrow
Solution Approach 1:
The patent changes the chemical structure parameters of electron donors by introducing aromatic 1,4-diether compounds with specific molecular structures (formula I, II, or III) containing adjustable R1, R2, and R3 groups. This structural parameter change enables broader molecular weight distribution while maintaining high catalyst activity, resolving the contradiction between activity enhancement and distribution broadening.
Solution Approach 2:
The patent creates a composite electron donor system combining aromatic 1,4-diether (internal electron donor) with external electron donors such as 1,3-diether or organic acid esters. This composite approach synergistically improves catalyst activity while the dual electron donor system broadens molecular weight distribution, addressing both limitations of conventional single electron donor systems.
2Productivity
If aromatic 1,3-diether is used as internal electron donor to achieve highest catalyst activity, then catalyst activity is significantly enhanced, but molecular weight distribution becomes narrow which restricts application
Solution Approach 1:
The patent segments the electron donor function into two parts: aromatic 1,4-diether as internal electron donor (providing high activity) and additional external electron donors (1,3-diether or organic acid esters) as supplementary components (broadening distribution). This functional segmentation allows each component to optimize its specific role, achieving both high activity and broad distribution simultaneously.
Solution Approach 2:
The patent introduces external electron donors (1,3-diether or organic acid esters) as intermediary substances that mediate between the high-activity aromatic 1,4-diether internal donor and the polymerization reaction. These intermediaries broaden molecular weight distribution while allowing the internal donor to maintain high catalyst activity, resolving the contradiction.
3Reliability
If conventional electron donors are used to achieve acceptable catalyst performance, then catalyst activity is moderate, but isotacticity control and molecular weight distribution adjustment are limited
Solution Approach 1:
The patent creates a dynamic and adjustable electron donor system where the types and ratios of internal (aromatic 1,4-diether) and external (1,3-diether or organic acid esters) electron donors can be varied. This dynamic composition allows real-time adjustment of isotacticity and molecular weight distribution parameters while maintaining reliable catalyst performance, enabling flexible adaptation to different polymerization requirements.
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 use of aromatic 1,4-diethers as internal electron donors in the catalyst system significantly increases catalytic activity, adjusts isotacticity and molecular weight distribution, and improves the flowability and apparent density of polypropylene, enabling broader application in olefin polymerization and copolymerization reactions.
Implementation Method 1
novel internal electron donors, specifically aromatic 1,4-diethers, which are used in combination with organic acid esters and 1,3-diethers to enhance catalyst activity
Data Source
AI summary
The catalyst for olefin polymerization contains three components A, B and C. The component A is a solid catalyst containing titanium, magnesium, chlorine element and an internal electron donor, the internal electron donor consists of 1,4-diether [2,2′-dialkoxy-1,1′-biphenyl, 2,2′-dialkoxy-1,1′-binaphthalene, 10,10′-dialkoxy-9,9-biphenanthrene]and organic acid ester or 1,3-diether [9,9-bis(methoxymethyl)fluorine, 2,2-dialky 1-1,3-dimethoxypropane]; the component B is an organoaluminum compound; the component C is external electron donor-organic silicon compound or the 1,4 aromatic diether. The catalyst has high catalytic activity, and can be adjusted in the range from 40,000 to 150,000 gPP/gCat when used in propylene polymerization. The polymer made therefrom has isotactivity of 80 to 99 percent and the molecular weight distribution can be adjusted in a wide range. The invention provides a novel method for preparing the 1,4 aromatic diether.