Alkyl Ether Sulfate Surfactant Thickening via EO-PO Ratio Control
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Solution Overview
Problem
Current surfactants derived from synthetic and natural alcohols exhibit different properties, with natural alcohol-derived surfactants lacking low-temperature stability, limiting their use in various applications, and existing thickeners for aqueous surfactant solutions either reduce solubility or require high amounts of inorganic salts, causing viscosity and irritation issues.
Innovation Solution
A surfactant composition comprising an alkyl ether sulfate with a specific structure, represented by the formula RO-(PO)m(EO)nSO3M, where R is a linear alkyl group, PO and EO represent propyleneoxy and ethyleneoxy groups, and m and n are within specific mole ranges, is produced through steps involving propylene oxide and ethylene oxide addition followed by sulfation and neutralization, offering enhanced thickening properties even at low inorganic salt concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If natural alcohol-derived surfactants are used, then high foaming ability and high emulsifying ability are improved, but low-temperature stability deteriorates
Solution Approach 1:
The invention changes the chemical structure parameters of the surfactant by using linear alcohols with 12-24 carbon atoms as raw materials and controlling the ethylene oxide addition amount (0.5-2.0 mol per mol of alcohol) and propylene oxide addition amount (0.1-0.9 mol per mol of alcohol) to optimize both foaming ability and low-temperature stability
Solution Approach 2:
The invention creates a composite surfactant structure combining linear alkyl group, ethylene oxide units, and propylene oxide units in specific ratios to achieve both high foaming ability and improved low-temperature stability compared to conventional natural alcohol-derived surfactants
2Stability of the object's composition
If synthetic alcohol-derived surfactants are used, then low-temperature stability is improved, but high foaming ability and high emulsifying ability deteriorate
Solution Approach 1:
The invention changes the surfactant structure by using linear alcohols (avoiding branched structures) and precisely controlling the amounts of ethylene oxide and propylene oxide added, thereby achieving both low-temperature stability and high foaming ability simultaneously
Solution Approach 2:
The invention develops a composite surfactant molecule with linear alkyl chain and controlled ethylene/propylene oxide units that combines the low-temperature stability of synthetic surfactants with the high foaming ability characteristic of natural alcohol-derived surfactants
3Force
If conventional thickeners (fatty acid alkanolamides) are added to aqueous surfactant solutions, then viscosity is improved, but solubility deteriorates and irritation increases
Solution Approach 1:
The invention extracts the thickening function from the surfactant molecule itself by incorporating specific ethylene oxide and propylene oxide units into the surfactant structure, eliminating the need to add separate thickener substances that cause irritation and solubility problems
Solution Approach 2:
The surfactant molecule is designed to perform multiple functions simultaneously: it provides both the primary surfactant action (foaming, emulsifying) and the thickening function, eliminating the need for separate additive substances
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 surfactant composition achieves a high thickening effect with reduced inorganic salt usage, maintaining stability and performance across various applications, including detergents and cosmetics, while avoiding the drawbacks of existing thickeners.
Implementation Method 1
an aqueous AS or AES solution has a low viscosity in this concentration range and it is necessary to adjust the aqueous solution so that the solution has a proper viscosity corresponding to its use
Implementation Method 2
step (I): a step of adding propylene oxide in an average amount exceeding 0 mol and less than 1 mol to 1 mol of an alcohol having a linear alkyl group having 12 to 24 carbon atoms; step (II): a step of adding ethylene oxide to the propylene oxide addition product
Implementation Method 3
step (III) : a step of sulfating the alkoxylate obtained in the step (II) and neutralizing the resultant
Data Source
AI summary
The invention relates to a surfactant composition containing an alkyl ether sulfate represented by the following formula (1): RO - (PO)m(EO)nSO3M (1) wherein R represents a linear alkyl group having 8 to 24 carbon atoms, PO and EO represent a propyleneoxy group and anethyleneoxygroup, respectively, m and n denote the average numbers of added moles of PO and EO, respectively, and are numbers meeting: 0 < m < 1 and 0 < n ≦ 2.3, respectively, and M represents a cation.