Vegetable Oil Polyol Purification for Low-Odor Polyurethane Foam
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing polyols from vegetable oils face challenges such as the need for solvents, prolonged production times, unfavorable smell, reduced mechanical properties, instability over time, high volatile organic compound emissions, and unsuitable mechanical properties due to unreacted double bonds and nucleophiles.
Innovation Solution
A two-stage process involving partial hydrogenation of vegetable oils to reduce double bonds, followed by solvent-free epoxidation and rigorous purification of both epoxidized oil and polyol, using a controlled amount of nucleophile and specific purification methods to achieve a polyol with reduced unsaturated bonds and volatile compounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If vegetable oil is used for polyol production without double bond reduction, then renewable source utilization is improved, but stability over time deteriorates due to oxidation of unsaturated bonds
Solution Approach 1:
The patent applies preliminary hydrogenation to reduce the iodine value of vegetable oil from 105-120 to below 100 g/100g before epoxidation. This preliminary action of reducing unsaturated bonds prevents subsequent oxidation and instability issues while maintaining the renewable nature of the原料.
Solution Approach 2:
The patent changes the chemical parameter of the vegetable oil by controlling the iodine value through partial hydrogenation. This parameter change from high unsaturation (IV 105-120) to reduced unsaturation (IV <100) resolves the contradiction between renewable source utilization and long-term stability.
2Productivity
If conventional epoxidation with high acetic acid content is used, then epoxidation efficiency is improved, but unfavorable smell and volatile organic compound emissions worsen
Solution Approach 1:
The patent changes the concentration parameter of acetic acid from conventional high concentrations (30-100%) to a reduced concentration range of 5-15%. This parameter change maintains adequate epoxidation efficiency while significantly reducing unfavorable smell and volatile organic compound emissions.
Solution Approach 2:
The patent converts the harmful effect of acetic acid (smell and VOC emissions) into a beneficial outcome by using the minimum necessary amount at reduced concentration. The acetic acid still enables epoxidation but its harmful volatile properties are minimized through careful parameter optimization.
3Manufacturing precision
If large excess of nucleophile is used in ring opening, then complete epoxy group conversion is improved, but mechanical properties of foam deteriorate
Solution Approach 1:
The patent applies partial action by using a controlled, moderate excess of nucleophile (1.05-1.20 moles per mole of epoxy groups) rather than large excess. This achieves sufficient epoxy group conversion (95-99%) while avoiding the negative impact on foam mechanical properties that results from excessive nucleophile usage.
4Loss of time
If traditional purification methods are used, then production time is reduced, but purity of polyol and foam properties deteriorate
Solution Approach 1:
The patent segments the purification process into distinct sequential steps: water washing to remove acetic acid, neutralization with base to remove catalyst, and drying to remove water. This segmented approach achieves high purity (acid value <1.0 mg KOH/g, water content <0.05% by weight) while managing production time efficiently.
Solution Approach 2:
The patent performs preliminary purification steps immediately after reaction, including water washing and neutralization before final drying and product formulation. This preliminary action ensures high purity is achieved early in the process, preventing contamination accumulation and ensuring consistent foam properties.
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 polyol with improved stability, imperceptible smell, and mechanical properties comparable to petrochemical polyols, enabling the production of flexible polyurethane foams with enhanced durability and reduced emissions.
Implementation Method 1
epoxidation of the mixture from step a) by adding hydrogen peroxide for 90 to 120 minutes at a constant reaction temperature of 50 - 65°C
Implementation Method 2
a mixture of acids: 80% acetic acid and 95-98% sulfuric acid (VI)
Implementation Method 3
drying the organic layer by heating to a temperature in the range of 80 - 90°C under pressure below manometric zero while stripping with the nonreactive gas
Data Source
AI summary
The invention relates to a method for obtaining a natural polyol (NOP) from a vegetable oil with a reduced content of unsaturated bonds, using a reduced amount of nucleophile and double purification. The invention also relates to a polyol obtained by such a method and the use of such a natural polyol for the production of polyurethane foam with favorable smell and mechanical properties.