Multiblock Copolymer Preparation With Continuous-Batch Polymerization
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Solution Overview
Problem
Conventional methods for preparing polyolefin-polystyrene-based multiblock copolymers face challenges in achieving uniform structure and excellent physical properties due to difficulties in heat removal, reactant recycling, and concentration control during batch-type polymerization, leading to increased costs and non-uniform properties.
Innovation Solution
A method involving continuous type coordination polymerization of ethylene and alpha-olefin-based monomers followed by batch type anionic polymerization of styrene-based monomers, using hafnium and organozinc compounds, ensures uniformity and improved physical properties by controlling reaction conditions and catalyst activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If batch type polymerization is used for both coordination and anionic polymerization, then flexibility in operation is maintained, but heat removal becomes difficult and productivity decreases
Solution Approach 1:
The patent divides the polymerization process into two separate segments: continuous type coordination polymerization for the polyolefin block and batch type anionic polymerization for the polystyrene block. This segmentation allows each stage to be optimized independently - the continuous process efficiently handles heat removal during the exothermic coordination polymerization, while the batch process provides operational flexibility for the subsequent anionic polymerization.
Solution Approach 2:
The patent implements continuous type coordination polymerization to maintain continuous useful action during the polyolefin block formation. This continuous process enables sustained productivity and efficient heat removal through the reaction system, avoiding the periodic interruptions and heat accumulation problems associated with batch processing for this stage.
2Manufacturing precision
If batch type polymerization is used, then operational flexibility is maintained, but concentration control becomes limited and structure uniformity deteriorates
Solution Approach 1:
The patent segments the polymerization process into continuous coordination polymerization for uniform polyolefin block formation and batch anionic polymerization for polystyrene block addition. The continuous stage ensures uniform monomer concentration and catalyst distribution, producing a consistent polyolefin backbone that serves as a uniform substrate for the subsequent batch anionic polymerization.
Solution Approach 2:
The patent changes the operational mode parameter from batch to continuous for the coordination polymerization stage. This parameter change enables precise control of monomer feed rates, catalyst concentration, and reaction conditions, resulting in uniform polyolefin block structure with consistent molecular weight and composition that facilitates better overall copolymer uniformity.
3Strength
If conventional two-step process with hydrogenation is used, then thermoplastic elastomer properties are achieved, but manufacturing cost increases significantly
Solution Approach 1:
The patent extracts and eliminates the hydrogenation step from the conventional two-step process. By using coordination polymerization with specific catalysts during the polymerization stage, the method directly produces the desired polyolefin-polystyrene multiblock copolymer structure without requiring subsequent hydrogenation, thereby reducing manufacturing steps and costs while maintaining thermoplastic elastomer properties.
Solution Approach 2:
The patent performs the saturation of double bonds preliminarily during the coordination polymerization stage itself through careful selection of catalysts and conditions, rather than requiring a separate post-polymerization hydrogenation step. This preliminary action integrates what was previously a separate expensive step into the main polymerization process, reducing overall manufacturing cost.
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 approach enhances productivity and reduces manufacturing costs, resulting in polyolefin-polystyrene-based multiblock copolymers with improved tensile properties suitable for various industrial applications.
Implementation Method 1
preparing a polyolefin by performing coordination polymerization of ethylene and an alpha-olefin-based monomer, while continuously injecting a hafnium compound, an organozinc compound
Implementation Method 2
performing anionic polymerization of the polyolefin and a styrene-based monomer in the presence of an alkyllithium compound
Data Source
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AI summary
The present invention relates to a method for preparing a polyolefin-polystyrene-based multiblock copolymer having a uniform structure and showing excellent physical properties through continuous type coordination polymerization and batch type anionic polymerization.