RAFT Polymerization of Acrylic Acid Using Sulphur Transfer Agents
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Solution Overview
Problem
Current methods for synthesizing homopolymers and copolymers of acrylic acid using controlled radical polymerization, such as RAFT, often require organic solvents, leading to environmental and health concerns, and result in high polymolecularity indices and low conversion rates, making them unsuitable for efficient dispersion and grinding applications.
Innovation Solution
A process for synthesizing homopolymers and copolymers of acrylic acid using RAFT-type controlled radical polymerization in an aqueous medium without organic solvents, employing non-odorous transfer agents to achieve low polymolecularity indices and high conversion rates, and incorporating specific end-group patterns for improved dispersion and grinding properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If controlled radical polymerization is performed using conventional methods, then polymerization can proceed, but the polymolecularity index is high and conversion rate is low
Solution Approach 1:
The invention changes the chemical parameters of the polymerization system by introducing specific transfer agents with defined structures (formula I) and using redox initiation systems with specific component ratios. This enables simultaneous achievement of low polymolecularity index (under 2.2) and high conversion rate (over 90%) by optimizing the chemical environment for controlled chain growth and termination.
Solution Approach 2:
The transfer agent acts as an intermediary substance that mediates between the growing polymer chains and the monomer. It controls the polymerization process by regulating chain transfer reactions, enabling precise control over molecular weight distribution while maintaining high monomer conversion through its specific chemical structure and reactivity.
2Productivity
If organic solvents are used in the polymerization process, then polymerization can proceed efficiently, but environmental and health concerns arise
Solution Approach 1:
The invention changes the physical state parameter of the reaction medium from organic solvent-based to water-based. This substitution eliminates the harmful effects of organic solvents while maintaining polymerization efficiency through the use of water-soluble transfer agents and redox initiation systems that function effectively in aqueous environments.
Solution Approach 2:
The invention replaces expensive and harmful organic solvents with water, which is abundant, non-toxic, and environmentally benign. This substitution follows the principle of using simpler, safer substances when possible, eliminating the need for costly solvent recovery and disposal processes while reducing environmental impact.
3Productivity
If conventional transfer agents are used, then polymerization can proceed, but odorous compounds are generated
Solution Approach 1:
The invention changes the chemical composition parameter of the transfer agent by selecting specific compounds with structures defined in formula (I) that do not contain odorous functional groups. These water-soluble transfer agents maintain high polymerization efficiency while eliminating unpleasant odors, making the process more suitable for industrial and laboratory applications.
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 process achieves polymers with a polymolecularity index under 2.2 and conversion rates over 90%, effectively functioning as grinding and dispersion agents for mineral matter, enhancing stability and efficiency in applications like paper coatings, paints, and water treatment.
Implementation Method 1
controlled radical polymerisation of the RAFT type
Implementation Method 2
using as a transfer agent compounds of formula (I′)... obtained by a process of controlled radical polymerisation of the RAFT type
Implementation Method 3
The MALDI TOF method enables the presence of the pattern of formula (I) at the end of the polymer chain according to the invention to be demonstrated. This method is a technique for time of flight analysis by mass spectrometry
Implementation Method 4
use as agents for the dispersion of mineral matter in water... aqueous dispersions of mineral matter dispersed with the polymers
Implementation Method 5
use, as agents to aid grinding and/or co-grinding of mineral matter in water
Data Source
AI summary
The invention concerns the polymers obtained by the use of sulphur compounds in a process for controlled radical polymerization in water of acrylic acid and/or acrylic acid with hydrosoluble monomers. It concerns also their uses as dispersant agents or agents to aid grinding and/or co-grinding of mineral matters in aqueous suspensions, and as dispersant agents incorporated directly in aqueous formulations containing mineral matters. Finally, the invention concerns the formulations of mineral matters obtained in this manner.