Hydrophobic Monomer Polymerization via Solid Oligomer Mediation
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Solution Overview
Problem
Emulsion polymerization of highly hydrophobic monomers is inefficient due to low diffusion rates through the aqueous phase, resulting in high residual monomer levels and limited copolymerization, which is overcome by using a solid grade oligomer to enhance solubility and particle nucleation.
Innovation Solution
Polymerizing hydrophobic monomers in the presence of a solid grade oligomer, such as styrene-acrylic or acrylic resin, which increases solubility and particle formation, allowing for higher hydrophobic monomer incorporation and reduced residual monomer levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If emulsion polymerization is used for highly hydrophobic monomers, then the process is simple and widely applicable, but the diffusion rate of monomers through the aqueous phase is too low resulting in high residual monomer levels
Solution Approach 1:
The patent uses a hydrophilic chain transfer agent as an intermediary substance that mediates between the hydrophobic monomer and the aqueous phase. The chain transfer agent has both hydrophobic and hydrophilic segments, allowing it to solubilize the hydrophobic monomer in the aqueous phase and facilitate its transport to polymer particles, thereby improving polymerization efficiency while maintaining process simplicity
Solution Approach 2:
The patent changes the chemical parameters of the polymerization system by introducing a hydrophilic chain transfer agent with specific molecular structure and properties. This parameter change enables the hydrophobic monomer to dissolve and diffuse effectively in the aqueous phase, transforming the system from one with poor monomer solubility to one with enhanced monomer availability for polymerization
2Productivity
If mini- or nano-emulsions are used to increase monomer diffusion, then particle surface area increases improving monomer access, but high shear equipment is required increasing process complexity
Solution Approach 1:
The hydrophilic chain transfer agent serves as a molecular mediator that eliminates the need for mechanical emulsification equipment. By forming soluble complexes with hydrophobic monomers, it creates a homogeneous aqueous solution that diffuses naturally to polymer particles without requiring high-shear homogenizers or ultrasonic processors
Solution Approach 2:
The patent replaces the mechanical system (high-shear equipment, homogenizers, ultrasonic processors) with a chemical system (hydrophilic chain transfer agent). The chemical action of the chain transfer agent in solubilizing and transporting monomers substitutes for the mechanical action of high-shear mixing, achieving the same goal of enhanced monomer diffusion without complex equipment
3Strength
If high amounts of hydrophobic monomer are used to achieve desired properties, then water resistance and adhesion improve, but copolymerization efficiency decreases due to low solubility
Solution Approach 1:
The hydrophilic chain transfer agent acts as a mediator that enables high concentrations of hydrophobic monomer to be effectively incorporated into the polymer. By forming soluble intermediates, it allows large amounts of hydrophobic monomer to participate in copolymerization reactions, achieving both high monomer incorporation and desired material properties
Solution Approach 2:
The patent creates a composite molecular system consisting of the hydrophilic chain transfer agent and hydrophobic monomer. This composite structure combines the water-solubility of the chain transfer agent with the hydrophobicity of the monomer, enabling the hydrophobic monomer to be effectively incorporated into the aqueous polymerization system at high concentrations
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
This method enables efficient copolymerization of high amounts of hydrophobic monomers, reducing residual monomer levels and improving polymerization rates, as demonstrated by low residual heptadecyl acrylate concentrations and efficient styrene-butadiene copolymerization.
Implementation Method 1
the diffusion rate of highly hydrophobic monomers through the aqueous phase is so low... using a solid grade oligomer to enhance solubility
Implementation Method 2
which increases solubility and particle formation, allowing for higher hydrophobic monomer incorporation
Data Source
AI summary
Described herein are methods of making a composition, the method comprising polymerizing monomers comprising a hydrophobic monomer in the presence of a solid grade oligomer, thereby forming a (co)polymer derived from the hydrophobic monomer, wherein the (co)polymer is derived from 5% by weight to 100% by weight of the hydrophobic monomer based on the total monomer weight. The hydrophobic monomer has a solubility in water of 0.2 g/100 g or less as measured at 20° C. The hydrophobic monomer comprises a substituted or unsubstituted C10-C22 alkyl (meth)acrylate, a substituted or unsubstituted C8-C20 alkenyl (meth)acrylate, a substituted or unsubstituted C5-C12 cycloalkyl (meth)acrylate, or a combination thereof. In some examples, the hydrophobic monomer can comprise lauryl (meth)acrylate, stearyl (meth)acrylate, heptadecyl (meth)acrylate, linoleyl (meth)acrylate, behenyl acrylate, cyclohexyl (meth)acrylate, isodecyl (meth)acrylate), nonyl (meth)acrylate, tridecyl (meth)acrylate, pentadecyl (meth)acrylate, 3-methylbut-2-enyl methacrylate, 3,7-dimethylocta-2,6-dienyl (meth)acrylate, or a combination thereof.