Superabsorbent Polymer Surface Crosslinking for Gel Bed Permeability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing superabsorbent polymers face challenges in achieving simultaneous improvements in gel bed permeability, absorbency under load, and suction power, as increasing silica coating for better permeability often compromises these properties.
Innovation Solution
A superabsorbent polymer with a crosslinked polymer structure, including a base polymer and a surface crosslinked layer, is developed, using water-soluble ethylene-based unsaturated monomers partially neutralized with acidic groups, and a surface crosslinking method involving epoxy compounds to enhance surface crosslinking density, thereby improving permeability and suction power while maintaining absorbency under load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If silica coating amount is increased to improve gel bed permeability, then gel bed permeability is improved, but absorbency under load and suction power deteriorate
Solution Approach 1:
The patent applies surface crosslinking technology to create a crosslinked layer only on the surface of the superabsorbent polymer particles, while maintaining the original absorbent properties in the core region. This local modification allows the surface to provide improved permeability through controlled porosity without compromising the bulk absorbency and suction power, thus resolving the contradiction between permeability improvement and absorbency maintenance.
Solution Approach 2:
The patent changes the physical and chemical parameters of the polymer surface through crosslinking treatment, including controlling the crosslinking degree, polymerization time, and temperature to achieve optimal surface porosity. By precisely controlling these parameters, the surface structure is modified to enhance permeability while the bulk properties remain intact, thereby improving gel bed permeability without sacrificing absorbency under load and suction power.
2Temperature
If degree of internal crosslinking is increased to improve gel bed permeability, then gel bed permeability is improved, but suction power deteriorates
Solution Approach 1:
The patent segments the crosslinking process into two distinct zones: internal crosslinking and surface crosslinking. Internal crosslinking is controlled to provide structural stability and prevent excessive swelling, while surface crosslinking is enhanced to create porosity for improved permeability. This segmentation allows each region to fulfill its specific function without interfering with the other, thus improving gel bed permeability while maintaining suction power.
Solution Approach 2:
The patent transitions from uniform bulk crosslinking to spatially differentiated crosslinking by introducing a surface crosslinked layer. This dimensional change in crosslinking distribution allows the interior to maintain high crosslinking density for structural integrity and the surface to have optimized porosity for fluid flow, thereby resolving the contradiction between permeability and suction power.
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 resulting superabsorbent polymer exhibits excellent gel bed permeability and suction power, effectively addressing the limitations of previous technologies by maintaining or improving absorbency under load, making it suitable for hygiene products like diapers.
Implementation Method 1
A superabsorbent polymer (SAP) is a type of synthetic polymeric materials capable of absorbing moisture from about 500 to 1000 times its own weight
Implementation Method 2
a surface crosslinked layer including the additionally crosslinked polymer of the base polymer, which is formed on the base polymer
Data Source
AI summary
Provided are a superabsorbent polymer and a preparation method thereof. The superabsorbent polymer according to the present invention has excellent gel bed permeability (GBP) and suction power, thereby being usefully applied to hygiene products such as diapers.