Foam Polyurethane Microcellular Structure Impact Resilience
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Solution Overview
Problem
Conventional foam polyurethane materials face a trade-off between achieving lightweight and high impact resilience, with higher expansion rates leading to interconnected cells and stress concentration, limiting the simultaneous attainment of both properties.
Innovation Solution
A foam polyurethane material is produced using an isocyanate-terminated prepolymer with a specific isocyanate group content range, which reacts with a polyol and catalyst to form a composition that suppresses cell unification, resulting in a material with a high number of microcells, achieving lightweight and high impact resilience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If higher expansion rate is used to achieve lightweight, then weight is reduced, but cell interconnection occurs causing stress concentration and reduced resilience
Solution Approach 1:
The patent changes the chemical composition parameters of the polyisocyanate system by incorporating a specific ratio of cyclic polyisocyanate (1,3-propanesultone derivative) alongside conventional polyisocyanates. This compositional parameter change modifies the foaming kinetics and cell structure development, enabling high expansion rates without cell coalescence, thus achieving lightweight properties while maintaining impact resilience through controlled microcellular structure formation
Solution Approach 2:
The patent employs a composite polyisocyanate system combining multiple isocyanate compounds (aromatic polyisocyanate, aliphatic polyisocyanate, and cyclic polyisocyanate in specific ratios) to achieve synergistic effects. This composite approach allows the material to exhibit both high expandability for lightweight structure and controlled cell morphology for maintained resilience, resolving the contradiction between weight reduction and reliability
2Volume of moving object
If higher expansion rate is used to achieve lightweight, then volume increases, but cell size increases and stress concentration occurs
Solution Approach 1:
The patent utilizes parameter changes in the polyisocyanate composition (specifically incorporating 5-50 mass% cyclic polyisocyanate) to control foaming kinetics, enabling high volume expansion while maintaining fine cell size distribution. This prevents stress concentration by ensuring uniform stress distribution across numerous small cells rather than few large cells, thus maintaining strength despite increased volume
3Ease of manufacture
If conventional polyisocyanate composition is used, then manufacturing is simple, but cell structure becomes coarse with interconnection
Solution Approach 1:
The patent modifies the manufacturing approach by changing the chemical composition parameters of the polyisocyanate system. By incorporating cyclic polyisocyanate (1,3-propanesultone derivative) in specific ratios (5-50 mass%), the system achieves fine cell structure control with high expansion rates. This parameter change maintains manufacturing simplicity while dramatically improving cell structure precision, eliminating the need for complex processing steps
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 method produces a foam polyurethane material with improved lightweight properties and high impact resilience, as evidenced by increased cell density and enhanced mechanical properties such as impact resilience, compression set, and strength at break.
Implementation Method 1
a foam polyurethane material which is a reaction-foaming-product of a composition containing a monomer of a polyisocyanate (a), an isocyanate-terminated prepolymer (b) containing 0.3 mass% or more and less than 5 mass% of an isocyanate group, a polyol (c), and a catalyst
Data Source
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AI summary
A foam polyurethane material is a reaction-foaming-product of a composition containing a polyisocyanate (a), an isocyanate-terminated prepolymer (b) containing 0.3 mass% or more and less than 5 mass% of an isocyanate group, a polyol (c), and a catalyst.