Dicarbamate Catalyst Component for Propylene Polymerization
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Solution Overview
Problem
Conventional catalyst systems for propylene polymerization using phthalates as internal donors raise health concerns and fail to achieve an acceptable balance of activity and stereospecificity for industrial applications.
Innovation Solution
A catalyst component comprising Mg, Ti, and a specific class of electron donors based on dicarbamate groups, where R1 and R2 are selected from hydrogen and C1-C15 hydrocarbon groups, and A is a bivalent bridging group, is used to support Ti atoms on a Mg dihalide, offering improved activity and stereospecificity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phthalates are used as internal donors in Ziegler-Natta catalysts, then good activity and stereospecificity are achieved, but health concerns arise due to medical issues associated with their use
Solution Approach 1:
The patent replaces phthalate esters with dicarbamate compounds that have comparable catalytic performance but no associated health risks. The dicarbamates serve as functional substitutes that achieve the same technical purpose (providing stereospecificity and activity) without the harmful effects of phthalates, effectively replacing a harmful substance with a safe alternative.
2Ease of manufacture
If amino acid derivatives with one carbamate group and one free ester function are used as internal donors, then catalyst preparation is simplified, but activity and stereospecificity become very low
Solution Approach 1:
The patent changes the chemical structure parameters of the internal donor from amino acid derivatives (with one carbamate and one ester group) to dicarbamate compounds (with two carbamate groups). This structural parameter change fundamentally improves both activity and stereosspecificity while maintaining ease of manufacture, as the dicarbamates can still be prepared through straightforward condensation reactions.
Solution Approach 2:
The patent creates a composite catalyst system where the internal donor is a dicarbamate compound with specific structural features (two carbamate groups attached to a bridging group). This composite structure combines the benefits of ease of preparation with high catalytic activity and stereosspecificity, overcoming the limitations of previous single-functional donor structures.
3Device complexity
If amino ester derivatives are used as internal donors, then structural simplicity is achieved, but the balance of activity and stereospecificity remains unacceptable for industrial exploitation
Solution Approach 1:
The patent modifies the donor structure parameters by introducing two carbamate groups instead of one ester group, while maintaining structural simplicity. The dicarbamate structure with bridging groups provides the necessary complexity for high activity and stereosspecificity without introducing excessive structural complexity that would complicate manufacturing or application.
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 dicarbamate-based catalyst system achieves an excellent balance of activity and stereospecificity, overcoming the limitations of phthalate-based systems and providing a safer, more effective alternative for propylene polymerization.
Implementation Method 1
a catalyst component for the polymerization of olefins comprising Mg, Ti and an electron donor selected from a specific class of dicarbamates wherein the catalyst component comprises Ti atoms supported on a Mg dihalide
Data Source
AI summary
Catalyst component for the polymerization of olefins comprising Mg, Ti and an electron donor of formula (I)Where R1 and R2, independently, are selected from hydrogen and C1-C15 hydrocarbon groups, optionally contain an heteroatom selected from halogen, P, S, N, O and Si, which can be fused together to form one or more closed cycles and A is a bivalent bridging group.