Superabsorbent Polymer Preparation via Gel Freezing and Pulverization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The preparation of superabsorbent polymers often results in the generation of fine particles, which deteriorate the physical properties of the final product and increase energy consumption due to agglomeration and reprocessing needs, especially when using traditional chopping methods that struggle with the elasticity and adhesiveness of water-containing gel polymers.
Innovation Solution
A method involving the crosslinking-polymerization of water-soluble ethylenically unsaturated monomers with internal crosslinking agents, followed by primary and secondary pulverization and drying steps in the presence of a surfactant, to control particle size and agglomeration, reducing the water content to 45-80% during primary drying, and subsequent secondary pulverization to minimize fine particle generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional chopping methods are used to pulverize water-containing gel polymer, then particle size can be reduced, but fine particles are generated due to elasticity and adhesiveness of the polymer
Solution Approach 1:
The patent applies preliminary freezing of the water-containing gel polymer before pulverization. By freezing the polymer in advance, the water inside forms ice crystals that act as internal spacers, preventing the polymer chains from adhering to each other during subsequent chopping. This preliminary action eliminates the adhesiveness problem that causes fine particle generation while still achieving the desired particle size reduction.
Solution Approach 2:
The patent changes the physical state parameter of the water-containing gel polymer from liquid/soft gel state to frozen solid state before pulverization. This parameter change (freezing) fundamentally alters the mechanical properties of the polymer, making it brittle and easy to chop without agglomeration, thereby resolving the contradiction between achieving small particle size and preventing fine particle generation.
2Productivity
If water-containing gel polymer is chopped into small particles, then drying efficiency can be improved, but agglomeration occurs due to adhesiveness
Solution Approach 1:
The patent performs preliminary freezing before the chopping and drying processes. This preliminary action prevents agglomeration during subsequent handling and drying by maintaining the polymer in a frozen, non-adhesive state. The freezing acts as a protective measure that preserves particle separation throughout the processing sequence, enabling efficient drying without agglomeration issues.
Solution Approach 2:
The patent converts the harmful adhesiveness of the water-containing gel polymer into a beneficial property by freezing it. The water that causes adhesiveness in liquid form becomes ice crystals that provide internal spacing and prevent particle bonding. This transforms the problematic moisture content into a useful freezing mechanism that prevents agglomeration while allowing efficient drying.
3Reliability
If multiple pulverization steps are performed to reduce particle size, then absorption properties can be improved, but fine particle generation increases
Solution Approach 1:
The patent performs a single pulverization step on frozen gel polymer instead of multiple steps on unfrozen polymer. The preliminary freezing enables complete particle size reduction in one operation, achieving the same or better absorption properties without the cumulative fine particle generation that occurs with repeated pulverization of unfrozen material.
Solution Approach 2:
The patent maintains the polymer in a continuous frozen state throughout the pulverization process, enabling uninterrupted size reduction in a single continuous operation. This continuous action on frozen material achieves the desired particle size distribution for good absorption properties without the intermittent processing and re-agglomeration that occurs in multiple steps, thereby minimizing fine particle generation.
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 significantly reduces the generation of fine particles, improves absorption properties, and results in superabsorbent polymers with uniform particle size distribution, enhanced absorption rates, and water retention capacity, suitable for ultra-thin sanitary materials.
Implementation Method 1
forming a water-containing gel polymer, in which a water-soluble ethylenically unsaturated monomer having acidic groups and an internal crosslinking agent are crosslinking-polymerized
Implementation Method 2
preparing a primary pulverized water-containing gel polymer by performing a primary water-containing gel pulverization of the water-containing gel polymer in the presence of a surfactant
Implementation Method 3
preparing a primary dry water-containing gel polymer by performing a primary moving type drying of the primary pulverized water-containing gel polymer
Data Source
AI summary
Provided is a method for preparing a superabsorbent polymer. More particularly, provided is a method for preparing a superabsorbent polymer exhibiting remarkably reduced water-soluble components and generation of fine particles and exhibiting excellent absorption properties.