Aviation Phosphate Ester Fluids with Acid Scavengers
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Solution Overview
Problem
Phosphate ester based functional fluids used in aircraft hydraulic systems face issues with acid build-up due to hydrolysis, leading to increased acidity and reduced service life, as current acid scavengers are ineffective in neutralizing carboxylic acids and strong acids like alkyl phosphoric acids.
Innovation Solution
A combination of alkyl epoxy and carbodiimide acid scavengers is used in phosphate ester based functional fluids to effectively neutralize both carboxylic and alkyl phosphoric acids, enhancing the fluid's acidity control and service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If phosphate esters are used as base stocks in aircraft hydraulic fluids, then fire resistance is improved, but hydrolytic stability deteriorates leading to acid build-up
Solution Approach 1:
The patent introduces acid scavengers (amines or carbodiimides) as intermediary substances that mediate between the phosphate ester base stock and the harmful carboxylic acids produced during hydrolysis. These acid scavengers neutralize the acids, preventing the deterioration of hydrolytic stability while maintaining the fire resistance benefits of phosphate esters.
Solution Approach 2:
The patent converts the harmful effect of hydrolysis (acid production) into a manageable condition by using acid scavengers that specifically target and neutralize carboxylic acids. This approach transforms the problematic acid build-up into a controlled neutralization process, extending fluid service life while preserving the inherent fire resistance of phosphate esters.
2Object-generated harmful factors
If epoxide acid scavengers are used in phosphate ester fluids, then some acid neutralization is achieved, but they are ineffective against carboxylic acids and strong acids like alkyl phosphoric acids
Solution Approach 1:
The patent changes the chemical parameter of the acid scavenger from epoxide to amine or carbodiimide, which fundamentally alters the scavenging mechanism. Amines and carbodiimides have different chemical reactivity profiles that enable them to effectively neutralize both carboxylic acids and strong acids like alkyl phosphoric acids, overcoming the limitations of epoxide-based scavengers.
Solution Approach 2:
The patent employs composite acid scavenging systems combining amines and/or carbodiimides with phosphate esters, creating a synergistic formulation where the acid scavenger components work together to address multiple acid types. This composite approach provides comprehensive acid neutralization across different acid strengths and types.
3Quantity of substance
If phosphate esters absorb atmospheric moisture, then water concentration increases, but this accelerates hydrolysis and reduces fluid service life
Solution Approach 1:
The patent applies preliminary action by incorporating acid scavengers (amines or carbodiimides) into the phosphate ester formulation before exposure to moisture. These scavengers are positioned to immediately neutralize any carboxylic acids formed during hydrolysis, preventing the cumulative acid build-up that would otherwise accelerate degradation and reduce service life.
Solution Approach 2:
The patent implements self-service through acid scavengers that automatically neutralize acids as they form during hydrolysis. The amine or carbodiimide components continuously react with carboxylic acids and strong acids, providing self-regulating protection that extends fluid service life without requiring external intervention or moisture exclusion measures.
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 combination of alkyl epoxy and carbodiimide acid scavengers significantly reduces acidity, extending the service life of the fluid and maintaining its performance in aircraft hydraulic systems by effectively neutralizing acids produced during hydrolysis.
Implementation Method 1
a combination of alkyl epoxy and carbodiimide acid scavengers is used in phosphate ester based functional fluids to effectively neutralize both carboxylic and alkyl phosphoric acids
Implementation Method 2
Like all esters, these fluids have the potential to hydrolyze (react with water to form alcohols and acids)
Data Source
AI summary
The present invention is an aviation phosphate ester functional fluid of enhanced acid scavenging properties comprising a phosphate ester base oil and a mixture of aliphatic epoxide and carbodiimide acid scavengers.