Diene Polymerisation Microstructure Control via Catalyst System
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Solution Overview
Problem
Commercially available polybutadienes have microstructures with uncontrolled cis-, trans-, and 1,2-vinyl units, requiring costly and technically challenging post-reactor mechanical blending to achieve desired properties, which is inefficient and difficult, especially for high molecular weight polymers with poor compatibility.
Innovation Solution
A process using a catalyst system comprising transition metal compounds like Cr, Mo, and Fe, Co, and Ni, along with a catalyst modifier and activators, to control the microstructure of polydienes by varying the ratio of transition metal compounds and modifier concentrations, allowing for controlled production of polydienes with desired cis-, trans-, and 1,2-vinyl contents without post-reactor blending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If post-reactor mechanical blending is used to control microstructure, then desired cis-, trans- and 1,2-vinyl contents can be achieved, but energy consumption increases and equipment costs rise
Solution Approach 1:
The invention applies preliminary action by controlling the microstructure during the polymerization reaction itself rather than after the reaction is complete. By using a catalyst system with specific transition metal compounds (Cr, Mo, W) and modifiers (phosphines, xanthogens, thiocyanides, carbon disulfide), the desired cis-, trans- and 1,2-vinyl configurations are formed in-situ during polymerization, eliminating the need for subsequent mechanical blending operations that would consume additional energy.
2Manufacturing precision
If post-reactor mechanical blending is used to control microstructure, then desired cis-, trans- and 1,2-vinyl contents can be achieved, but equipment costs and time increase
Solution Approach 1:
The invention performs the microstructure control action during the polymerization reaction itself rather than as a subsequent step. The catalyst system with transition metal compounds and modifiers establishes the desired polymer configuration in-situ, eliminating the need for separate post-reactor blending equipment and time-consuming mechanical mixing operations.
3Manufacturing precision
If post-reactor mechanical blending is used to control microstructure, then desired cis-, trans- and 1,2-vinyl contents can be achieved, but device complexity increases
Solution Approach 1:
The invention eliminates the need for separate post-reactor blending equipment by performing microstructure control during polymerization. The catalyst system with transition metal compounds and modifiers achieves the desired microstructure in-situ, reducing equipment complexity by removing the need for additional blending devices and associated mechanical systems.
4Manufacturing precision
If blending polymers with high molecular weight is performed, then desired microstructure can be achieved, but technical difficulty increases due to poor compatibility
Solution Approach 1:
The invention avoids the technical difficulties of blending high molecular weight polymers by controlling microstructure during polymerization itself. The catalyst system with transition metal compounds and modifiers forms the desired polymer configuration in-situ, eliminating the need for subsequent blending operations that would be technically difficult due to poor compatibility and high molecular weight.
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
This process enables the production of polydienes with controlled microstructures, achieving desired ratios of trans/cis and 1,2-vinyl contents, thereby simplifying the production process and improving polymer properties without the need for post-reactor blending, reducing energy and equipment costs.
Implementation Method 1
A process using a catalyst system comprising transition metal compounds like Cr, Mo, and Fe, Co, and Ni, along with a catalyst modifier and activators, to control the microstructure of polydienes
Data Source
AI summary
Process for producing homopolymers or copolymers of conjugated dienes by contacting monomeric material including at least one conjugated diene with a catalyst system comprising (A) a first transition metal compound selected from Cr, Mo and W compounds, and a second transition metal compound selected from Fe, Co and Ni compounds, (B) a catalyst modifier and, optionally, (C) one or more catalyst activators.