Isocyanate-Modified Polyester-Epoxide Polymer Flexibility
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Solution Overview
Problem
Existing epoxy-based products face challenges in achieving desirable flexibility at a low cost while maintaining other important properties, often having high glass-transition temperatures and low ultimate elongations.
Innovation Solution
The development of isocyanate-modified polyester-epoxide polymer (i-PEEP) compositions, which are reaction products of a polyepoxide compound, a polyisocyanate, and a polyol composition, specifically tailored to achieve increased elongation, lower glass-transition temperatures, and a balanced set of properties without relying on polyamine curatives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional epoxy-based products are used, then good chemical resistance and adhesion are achieved, but flexibility and ultimate elongation are poor with high glass-transition temperatures
Solution Approach 1:
The patent creates a composite polymer system combining polyester polyol, polyepoxide, and polyisocyanate components to form an i-PEEP composition that integrates the chemical resistance of epoxy with the flexibility of polyester polyurethane, achieving both durability and elastomeric properties in a single material system
Solution Approach 2:
The patent modifies the chemical composition parameters by incorporating polyester polyol with specific hydroxyl values (50-400 mg KOH/g) and polyisocyanate with NCO functionality (2.0-3.0), controlling the epoxy-to-hydroxyl ratio (0.2-2.0) to achieve desired glass-transition temperatures and elongation properties while maintaining chemical resistance
2Productivity
If polyamine curatives are used to cure epoxy resins, then rapid curing is achieved, but environmental concerns and cost issues arise
Solution Approach 1:
The patent introduces polyester polyol as an intermediary curing agent that reacts with epoxide groups to form the i-PEEP composition, providing an environmentally friendly alternative to polyamine curatives while maintaining acceptable curing characteristics and avoiding the harmful effects of conventional epoxy hardeners
Solution Approach 2:
The patent uses commercially available polyester polyols and polyisocyanates as cost-effective curing agents that eliminate the need for expensive or environmentally problematic polyamine curatives, making the i-PEEP composition economically viable for widespread application
3Ease of operation
If polyester polyol with high hydroxyl functionality is used to react with epoxy resins, then some flexibility improvement is achieved, but the products still have high glass-transition temperatures and limited elongation
Solution Approach 1:
The patent systematically adjusts multiple parameters including hydroxyl value (50-400 mg KOH/g), NCO functionality (2.0-3.0), and epoxy-to-hydroxyl ratio (0.2-2.0) to optimize the glass-transition temperature and elongation properties, moving beyond simple hydroxyl functionality increases to achieve balanced performance
4Reliability
If multiple step processes are used to synthesize i-PEEP compositions, then reaction control is improved, but manufacturing complexity and time increase
Solution Approach 1:
The patent combines the reaction of polyester polyol with polyepoxide and polyisocyanate into a single integrated process step, eliminating the need for separate intermediate isolation and purification steps while maintaining reliable reaction control through appropriate stoichiometric ratios and catalyst selection
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
i-PEEP compositions demonstrate improved flexibility, impact resistance, and variable or lower glass-transition temperatures, while being cost-effective and environmentally friendly, thus addressing the limitations of traditional epoxy-based products.
Implementation Method 1
The i-PEEP composition comprises a reaction product of a polyepoxide compound, a polyisocyanate, and a polyol composition
Data Source
AI summary
Isocyanate-modified polyester-epoxide polymer (i-PEEP) compositions are disclosed. The i-PEEP compositions comprise a reaction product of a polyepoxide compound, a polyisocyanate, and a polyester polyol composition. The ratio of epoxy equivalents to hydroxyl equivalents is within the range of 0.2 to 2. The i-PEEP index as defined herein is within the range of 100 to 200. The i-PEEP composition has a Tg within the range of -30°C to 35°C. Low- and elevated-temperature processes catalyzed by bases or Lewis acids for making the i-PEEP compositions are also disclosed. In a simple yet innovative approach, a new class of polymers useful for coatings, elastomers, adhesives, sealants, and other valuable products is assembled from readily available starting materials without reliance on the polyamines typically used to cure epoxy systems.