Membrane Separation of Vinylamine Polymers With Low Yield Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for removing salts and by-products from vinylamine-containing polymers are not practical on a commercial scale due to pressure drop and yield loss, and existing synthetic approaches affect polymer quality.
Innovation Solution
Utilizing nanofiltration and ultrafiltration membranes with specific molecular weight cut-offs to separate high molecular weight vinylamine-containing polymers from residual impurities, including salts and low molecular weight polymers, while retaining functional performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If activated media is used to filter salts, by-products, and low molecular weight vinylamine-containing polymers, then impurity removal is improved, but pressure drop increases and yield is lost
Solution Approach 1:
The patent employs porous membranes with specific pore size distributions to separate impurities from vinylamine-containing polymers. The membranes allow small molecules (salts, by-products, low molecular weight polymers) to pass through while retaining high molecular weight functional polymers, achieving impurity removal without the yield loss associated with activated media filtration
Solution Approach 2:
The patent changes the separation mechanism from adsorption (activated media) to size-based filtration (membranes). By adjusting membrane pore size and molecular weight cut-off parameters, the process achieves effective impurity removal while maintaining high polymer recovery, resolving the contradiction between manufacturing precision and substance loss
2Manufacturing precision
If activated media is used to filter salts, by-products, and low molecular weight vinylamine-containing polymers, then impurity removal is improved, but pressure drop increases
Solution Approach 1:
The patent replaces activated media with porous membrane filtration systems that have controlled pore structures. These membranes provide continuous filtration surfaces with optimized pore sizes that allow efficient impurity removal while maintaining lower pressure drops compared to the resistance encountered when using activated media beds
Solution Approach 2:
The patent substitutes the mechanical filtration mechanism of activated media (which requires high pressure to force fluid through resistant beds) with a membrane-based size exclusion mechanism. This substitution reduces the mechanical pressure requirements while achieving superior impurity removal through molecular size differentiation
3Manufacturing precision
If synthetic steps are modified to reduce impurity production, then impurity levels are reduced, but polymer quality and functionality are affected
Solution Approach 1:
The patent extracts impurities from the polymer solution through membrane filtration after synthesis is complete. This post-synthesis separation approach allows the use of robust, high-yield synthetic routes without compromising final polymer quality, as impurities are removed in a dedicated separation step that does not affect polymer functionality
Solution Approach 2:
The patent introduces membrane filtration as an intermediary step between synthesis and final product. This intermediary process selectively removes impurities while preserving the functional integrity of high molecular weight polymers, resolving the contradiction between reducing impurity levels and maintaining polymer quality
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 process achieves superior product performance by increasing the high molecular weight fraction of vinylamine-containing polymers, enhancing their efficacy in applications like papermaking.
Implementation Method 1
circulating the solution through a nanofiltration membrane and/or an ultrafiltration membrane thereby separating the vinylamine-containing polymer or retentate from residual impurities
Implementation Method 2
circulating the solution through a nanofiltration membrane and/or an ultrafiltration membrane thereby separating the vinylamine-containing polymer or retentate from residual impurities
Implementation Method 3
Liquid membrane separation is classified by the molecular weight cut-off (MWCO) when describing the various membranes
Data Source
AI summary
Provided is a method for the removal of salts and by-products from vinylamine-containing polymers. In particular, the method allows the removal of unwanted salts, by-products, spent initiators and short chain vinylamine-containing polymers while retaining the functional, higher molecular weight polymers that provide for desired product performance.