Graft Polyol Viscosity Reduction via Segmented Free Radical Polymerization
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Solution Overview
Problem
Conventional polyols derived from petroleum have environmental and financial drawbacks, and natural oil polyols require chemical modification to form polyurethane foams, leading to increased viscosity and reduced usability.
Innovation Solution
A graft polyol is formed using a natural oil polyol with at least 50% represented by a specific formula, combined with particles resulting from the reaction of a macromer polyol, polymerizable monomer, chain transfer agent, and free radical initiator, which increases bio-content and reduces viscosity, allowing for improved handling and physical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemical modification is performed on natural oil to enable polyurethane foam application, then reactivity with isocyanates is improved, but viscosity increases excessively and production costs increase
Solution Approach 1:
The patent segments the modification process into two distinct stages: first, grafting hydroxyl-containing groups to the natural oil backbone to create reactive sites; second, polymerizing these grafted groups to form the final polyol product. This segmentation allows control over viscosity at each stage, preventing the excessive viscosity increase that would occur with complete modification at once.
Solution Approach 2:
The patent applies preliminary action by first grafting hydroxyl-containing groups onto the natural oil before performing the polymerization reaction. This preliminary grafting creates reactive sites that enable subsequent polymerization while maintaining manageable viscosity levels during the intermediate stage, avoiding the need for complete chemical modification before polymerization.
2Strength
If chemically modified castor oil is used to form graft polyol, then physical properties of polyurethane foam are improved, but viscosity increases and usability is reduced
Solution Approach 1:
The patent employs parameter changes by controlling the degree of grafting and polymerization to optimize the balance between physical properties and viscosity. By adjusting parameters such as the amount of hydroxyl-containing groups grafted and the polymerization conditions, the patent achieves desirable foam physical properties while maintaining usability through controlled viscosity.
3Quantity of substance
If higher solids content is achieved in graft polyol, then bio-content and environmental benefits are increased, but viscosity increases and maximum achievable solids content is limited
Solution Approach 1:
The patent applies continuity of useful action by maintaining polymerization throughout the grafting process rather than completing all reactions beforehand. This continuous polymerization allows the formation of high molecular weight polymers with high solids content while the reaction conditions are controlled to prevent excessive viscosity increase, enabling higher bio-content without sacrificing manufacturability.
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 polyurethane articles exhibit improved physical properties and increased bio-content, comparable to or better than those made with petroleum-based polyols, with reduced reliance on petroleum-based products and enhanced environmental and economic benefits.
Implementation Method 1
The particles include the reaction product of a macromer polyol, a polymerizable monomer, a chain transfer agent, a free radical initiator and an additional amount of macromer polyol. The macromer polyol, the polymerizable monomer, the chain transfer agent, the free radical initiator and the additional macromer polyol react in the presence of the natural oil.
Data Source
AI summary
A graft polyol includes a natural oil including at least 50% by weight of a natural oil polyol. Particles are dispersed in the natural oil and comprise the reaction product of a macromer polyol, a polymerizable monomer, a chain transfer agent, and a free radical initiator. The macromer polyol and the polymerizable monomer react in the presence of the natural oil. The graft polyol is formed by providing the natural oil and providing the macromer polyol, the chain transfer agent, the free radical initiator, and the polymerizable monomer. The natural oil, the polymerizable monomer, the macromer polyol, the chain transfer agent, and the free radical initiator are combined, and the polymerizable monomer, the macromer polyol, the chain transfer agent, and the free radical initiator react to form particles dispersed in the natural oil.