Phosphorus Oxide Cotelomers for Thermally Stable Comb Polymers
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Solution Overview
Problem
Existing methods for producing comb polymers, such as superplasticizers and rheology modifiers, face challenges with thermal instability and low yield due to the decomposition of polyoxyalkyl side chains during esterification or amidation processes, limiting processing flexibility and requiring solvent removal steps.
Innovation Solution
The development of phosphorus oxide cotelomers with specific weight percentages of unsaturated carboxylic acids and methacrylic anhydride groups, which are processed into small particle sizes through spray drying and subsequent size reduction, allowing for rapid and efficient reaction with polyols without the need for solvent removal or catalysts, enabling the formation of thermally stable comb polymers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional chain transfer polymerization or high concentration initiator methods are used to produce polymers with molecular weight less than 15,000 daltons, then the polymerization process is efficient and produces desired molecular weight, but the resulting polymers are not thermally stable which limits processing flexibility
Solution Approach 1:
The invention changes the chemical composition parameters by incorporating phosphorus oxide groups (P=O) into the polymer backbone through controlled polymerization of phosphorus-containing monomers. This compositional parameter change fundamentally alters the thermal stability of the polymer without sacrificing polymerization efficiency, as the phosphorus oxide groups provide thermal stability while the polymerization process remains efficient.
2Ease of manufacture
If solvent assisted distillation, vacuum removal or inert gas sparging is used to remove water prior to esterification, then the esterification reaction can proceed, but the process complexity increases and additional processing steps are required
Solution Approach 1:
The invention extracts the water removal step from the overall process by using phosphorus oxide cotelomers that inherently have low water content due to the water-scavenging properties of phosphorus oxide groups during polymerization. This eliminates the need for separate water removal operations (distillation, vacuum removal, or sparging) before esterification, simplifying the process while maintaining manufacturability.
3Adaptability or versatility
If polyoxyalkyl side chains are used in comb polymers, then the polymers can function as superplasticizers and rheology modifiers, but the polyoxyalkyl side chains decompose during esterification or amidation resulting in low yield
Solution Approach 1:
The invention performs preliminary protection of the polyoxyalkyl side chains by incorporating them after the esterification/amidation reaction is complete, rather than attempting to protect them before reaction. The phosphorus oxide cotelomer structure enables this sequence by providing a reactive backbone that can undergo esterification/amidation with polyols or polyamines to form the polyoxyalkyl side chains in situ, avoiding decomposition that would occur if pre-formed polyoxyalkyl chains were subjected to harsh reaction conditions.
4Ease of operation
If small particle size phosphorus oxide cotelomers are used, then reactivity with polyols is enhanced and processing is simplified, but additional particle size reduction steps are required after spray drying
Solution Approach 1:
The invention optimizes the particle size parameters by controlling the spray drying conditions and subsequent milling to achieve a specific particle size distribution that balances reactivity and processing ease. The phosphorus oxide cotelomers are spray-dried to form particles, then lightly milled to reduce particle size to an optimal range that enhances surface area and reactivity with polyols while avoiding excessive fine powder generation that would require additional processing steps.
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 phosphorus oxide cotelomers exhibit enhanced reactivity and stability, leading to higher yield and quality comb polymers that can be processed under demanding conditions, suitable for various applications including cement admixtures and detergent builders, with reduced residual low molecular weight alcohols and no requirement for antioxidants.
Implementation Method 1
comprise particles or agglomerates of one or more phosphorus oxide cotelomer comprising the polymerization residue of from 20 to 99.2 wt.% of one or more unsaturated carboxylic acids
Implementation Method 2
The phosphorus oxide cotelomers of the present invention can be prepared by drying one or more cotelomer of methacrylic acid
Data Source
AI summary
The present invention provides compositions comprising particles or agglomerates of one or more phosphorus oxide telomer or cotelomer ((co) telomer) of one or more unsaturated carboxylic acids or anhydrides having a mean average particle size of from 2 µm to 1mm, preferably from 5 to 500 µm, preferably, comprising at least one carboxylic acid anhydride group. In addition, the present invention provides methods comprising aqueous solution addition polymerizing a monomer mixture of one or more unsaturated carboxylic acid in the presence of a phosphorus oxide acid or salt compound, drying the resulting copolymer at a temperature of from 120 to 230 °C and reducing its particle size to make the particle or agglomerate; methods may further comprise reacting the (co)telomer particle or agglomerate with one or more polyether polyol, alkyl polyether polyol, polyether amine or alkyl polyether amine, with heating, to form a comb polymer useful, e.g. as a superplasticizer or dispersant.