Polymer Adhesive Viscosity Reduction via Radical Shear Treatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Adhesives based on ethylene-propylene rubber and semi-crystalline olefinic polymers face challenges with high melt viscosity, which limits their application in scenarios requiring low viscosity and high polymer proportion.
Innovation Solution
Treating polymer blends of ethylene-propylene rubber and semi-crystalline olefinic polymers with radical donors under shear stress above the softening point to reduce melt viscosity, resulting in a polymer system with lower viscosity and narrowed molecular weight distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesives are made from EPR and semi-crystalline olefinic polymers to achieve high cohesive strength, then adhesive strength is improved, but melt viscosity becomes too high for applications requiring low viscosity
Solution Approach 1:
The patent applies parameter changes by modifying the molecular weight distribution of the polymer blend through controlled degradation processes. By changing the molecular parameters (reducing average molecular weight while maintaining composition), the adhesive achieves both low melt viscosity for ease of application and high cohesive strength for bonding performance.
2Strength
If polymer proportion in adhesive formulation is increased to improve adhesive performance, then adhesive strength is improved, but viscosity increases making it unsuitable for applications requiring low viscosity
Solution Approach 1:
The patent resolves this contradiction by changing the molecular weight distribution parameters of the polymer. Through controlled degradation, the adhesive formulation can incorporate high polymer proportions (improving strength) while maintaining low viscosity (improving applicability) by reducing the average molecular weight of the polymer chains.
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 a significant reduction in melt viscosity, enhancing the adhesive's flexibility and adhesion properties while maintaining high cohesive strength, making it suitable for various applications.
Implementation Method 1
treating at least one polymer blend starting material with at least one radical donor under shear stress at a temperature above the softening point of said polymer blend starting material
Implementation Method 2
treating at least one polymer blend starting material with at least one radical donor under shear stress at a temperature above the softening point
Data Source
AI summary
The present invention relates to an adhesive, comprising at least one polymer system obtained by a process for reducing the melt viscosity of at least one polymer blend starting material, wherein the process comprises the step of treating at least one polymer blend with at least one radical donor under shear stress at a temperature above the softening point of said polymer blend.