Multi-amine Polyester Dispersant via Anhydride Intermediate
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Solution Overview
Problem
Existing methods for synthesizing polyamine-polyester dispersants require high temperatures, leading to side reactions such as chain scission and yellowing of the polyamine, which affects the quality and consistency of the dispersants.
Innovation Solution
Converting carboxylic acid-ended polyester chains to anhydride intermediates and reacting them with polyamines at lower temperatures to form amide and salt linkages, reducing chain scission and yellowing, and allowing for more controlled molecular weight and architecture of the dispersants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high temperature reaction conditions are used to synthesize polyamine-polyester dispersants, then the reaction proceeds efficiently and water is effectively removed, but side reactions occur including chain scission and yellowing of the polyamine
Solution Approach 1:
The patent introduces an acid anhydride intermediate as a mediator in the reaction between carboxylic acid-ended polyester and polyamine. The polyester first reacts with the acid anhydride at elevated temperature to form anhydride-ended polyester, which then reacts with the polyamine at lower temperature. This intermediary step allows water removal and activation of the polyester without exposing the polyamine to high temperatures that cause yellowing and chain scission.
2Object-generated harmful factors
If the reaction temperature is reduced to prevent polyamine degradation, then yellowing and chain scission are minimized, but water removal becomes inefficient and reaction rate decreases
Solution Approach 1:
The patent performs preliminary action by first converting the carboxylic acid-ended polyester to anhydride-ended polyester before reacting with the polyamine. This preliminary conversion at elevated temperature efficiently removes water and activates the polyester chains. The activated anhydride groups then react readily with polyamine at lower temperatures, maintaining high reaction efficiency without requiring prolonged exposure to high temperatures that cause degradation.
3Ease of manufacture
If traditional direct reaction method is used between carboxylic acid polyester and polyamine, then the process is simple, but molecular weight and architecture control is difficult
Solution Approach 1:
The acid anhydride intermediate serves as a controlled mediator that enables precise molecular weight and architecture control. By first forming anhydride-ended polyester with defined chain lengths and functionalities, then reacting with polyamine, the process maintains simplicity while achieving better control over the final dispersant's molecular characteristics compared to direct reaction methods.
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 new method results in dispersants with improved stability, reduced yellowing, and enhanced performance in dispersing pigments and particulates across various media, with better control over molecular weight and microstructure, leading to consistent product quality.
Implementation Method 1
The carboxylic acid chain ends of the polyester are converted to anhydride groups by dehydration prior to the reaction with the multi-amine containing species
Implementation Method 2
reacted with the multi-amine containing species to form amide bonds
Data Source
AI summary
The present invention relates to a dispersant derived from anhydride functionalized polyester derived from carboxylic acid functionalized polyester. The anhydride functionalized polyester is then reacted with a multi-amine species forming amide and salt bonds. The technology allows lower reaction temperatures when the multi-amine species is present. The lower reaction temperature allows the use of a broader selection of polyester repeat units.