Epoxidized Polysulfide Adhesive for High Lap Shear Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing adhesive compositions lack sufficient bond strength and ease of application for bonding substrate materials, particularly in achieving high lap shear strength and displacement at failure.
Innovation Solution
A one-component adhesive composition comprising a resin blend of epoxidized polysulfide and epoxidized oil in a weight ratio of 20:1 to 1:1, combined with an epoxy-containing compound, which provides a sulfur-containing polymer backbone for enhanced bonding properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If existing adhesive compositions are used, then application is simple, but bond strength and displacement at failure are insufficient
Solution Approach 1:
The patent employs a composite adhesive system combining epoxidized polysulfide resin with epoxidized natural oil (castor, soybean, or linseed oil) in a weight ratio of 20:1 to 1:1. This composite formulation creates synergistic effects where the polysulfide provides structural integrity and the epoxidized oil enhances flexibility and bonding, achieving lap shear strength greater than 13 MPa and displacement at failure of at least 7 mm while maintaining ease of application
Solution Approach 2:
The patent modifies the chemical composition parameters by incorporating specific ratios of epoxidized polysulfide to epoxidized natural oil (20:1 to 1:1 weight ratio) and curing at low temperatures (80°C to 250°C). These parameter changes optimize the adhesive's mechanical properties, achieving high bond strength and displacement at failure without requiring high-energy curing processes
2Strength
If high bond strength is achieved, then mechanical properties improve, but curing conditions become more restrictive
Solution Approach 1:
The patent achieves high bond strength (greater than 13 MPa) by modifying the chemical composition rather than requiring high curing temperatures. The epoxidized polysulfide and epoxidized natural oil system can be cured at low temperatures (80°C to 250°C) while maintaining excellent mechanical properties, including displacement at failure of at least 7 mm, thus decoupling strength achievement from high-temperature requirements
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 adhesive composition achieves a lap shear strength greater than 13 MPa and displacement at failure of at least 7 mm, even when cured at low bake temperatures, demonstrating improved mechanical properties for various substrate materials.
Implementation Method 1
Adhesive compositions are utilized in a wide variety of applications to treat a variety of substrates or to bond together two or more substrate materials
Data Source
AI summary
Disclosed herein is an adhesive composition that includes a resin composition and an epoxy-containing compound. The resin composition includes an epoxidized polysulfide and an epoxidized oil. The epoxidized polysulfide is present in the adhesive composition in a weight ratio to the epoxidized oil of 20:1 to 1:1. Also disclosed is the adhesive composition in an at least partially cured state. Also disclosed is a method for treating a substrate comprising applying the adhesive composition to a surface of a substrate; and applying an external energy source to cure the composition. Also disclosed are substrates comprising the adhesive composition in an at least partially cured state.