Process to produce blended (meth)acrylate/vinyl ester resin cross-linkers
Inventors
Sadler, Joshua Matthew • La Scala, John Joseph • Palmese, Giuseppe R.
Assignees
Drexel University • United States Department of the Army
Publication Number
US-11718629-B2
Publication Date
2023-08-08
Expiration Date
2037-11-16
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Abstract
This invention outlines a method for synthesizing a blended resin system in a one pot reaction that may utilize, for example, bio-based anhydrosugars such as isosorbide as a principle component to produce isosorbide dimethacrylate and other monomeric materials for thermosetting applications. This invention establishes a one-pot procedure for reacting a hydroxy group containing compound with methacrylic anhydride in the first step and using the by-product methacrylic acid to react with glycidyl ethers to form additional methacrylate compounds in the second step. This methodology can be formulated to produce a wide array of resin systems that have controlled ratios of hydroxy group containing compound/cross-linker/reactive diluent. Additionally, the novel resin systems may be partially to fully bio-based, promoting global sustainability and reducing costs, and when free radically polymerized have properties that meet or exceed their petroleum derived counterparts.
Core Innovation
This invention provides a one-pot, two-step method for producing blended resin systems, notably utilizing bio-based anhydrosugars such as isosorbide as principal components to create isosorbide dimethacrylate and other monomeric materials suited for thermosetting applications. The process involves reacting an organic compound containing hydroxy groups with methacrylic anhydride in the first step to form (meth)acrylic esters and methacrylic acid. The by-product methacrylic acid is then used in the second step to react with various compounds containing epoxy groups to form additional methacrylate compounds, enabling the production of resin systems with controlled component ratios.
The invention addresses significant challenges associated with traditional vinyl ester resins, including their petroleum-based origins, which result in price volatility and environmental concerns, and their typically high viscosities requiring hazardous reactive diluents like styrene for processing. These diluents impose environmental regulatory burdens due to their classification as hazardous air pollutants and volatile organic compounds. The invention offers a bio-based alternative resin system that reduces or eliminates the need for these reactive diluents, improving sustainability and cost-effectiveness while retaining or exceeding the performance of petroleum-based counterparts.
Claims Coverage
The patent includes one independent claim that outlines a method for producing a curable resin through a one-pot, two-step reaction process. Three main inventive features are identified in this claim.
One-pot, two-step reaction method for resin production
A method comprising reacting an organic compound containing at least one hydroxy group with (meth)acrylic anhydride to produce a (meth)acrylic ester and (meth)acrylic acid, then reacting this product with an organic compound containing at least one epoxy group to form a second reaction product, followed optionally by blending this second product with up to about 75 wt.% of a reactive diluent to produce a curable resin.
Use of specific organic compounds in reaction steps
The organic compound with hydroxy groups includes alcohols such as methanol, ethanol, propanol, butanol, pentanol, hexanol, cyclohexanol, octanol or polyols like ethylene glycol, propylene glycol, polyethylene glycol oligomers, polypropylene glycol oligomers, hexanediol, glycerol, and pentaerythritol. The organic compound with epoxy groups includes glycidyl ethers such as diglycidyl ether of bisphenol A and its oligomers, diglycidyl ether of bisphenol F, glycidyl acrylate, glycidyl methacrylate, phenyl glycidyl ether, and their derivatives, as well as epoxidized oils, epoxidized cardanol, and epoxidized ricinoleic acid compounds.
Control of reaction conditions and stoichiometric ratios
Step i) is carried out until (meth)acrylic anhydride is consumed, in the presence of a basic catalyst, with molar ratios of hydroxy groups to (meth)acrylic anhydride from about 0.75 to about 1.25. Step ii) is conducted at temperatures from 25°C to about 100°C, using molar ratios of (meth)acrylic acid to glycidyl ether between about 0.1 to about 1.2 (preferably about 0.9 to 1.1). Reactive diluents blended are selected from a specific group including styrene and bio-based compounds. The process optionally includes curing by free-radical polymerization to form a cured resin.
The claims collectively cover a novel, efficient one-pot, two-step method for producing bio-based curable resins by methacrylation of hydroxy-containing organic compounds and subsequent reaction with epoxy-containing compounds, controlling stoichiometry and reaction conditions, optionally blending with reactive diluents, and curing to create high-performance thermosetting resin systems.
Stated Advantages
The one-pot, two-step synthesis eliminates the need for separation, purification, and blending steps, reducing costs and waste associated with traditional processes.
The method reduces or eliminates the need for hazardous reactive diluents, such as styrene, thereby addressing environmental and regulatory concerns.
It enables production of bio-based resin systems that have comparable or superior properties relative to petroleum-derived counterparts, including tunable glass transition temperatures and acceptable viscosities for processing.
The use of bio-based anhydrosugars promotes global sustainability and reduces dependency on petroleum feedstocks.
Documented Applications
The resins produced are useful as adhesives, coatings, composites, and resin matrices for fiber reinforced composites in military and commercial applications.
The cured polymers can serve as structural composites in automotive, aircraft (e.g., skins for airframe structures), composite armor, marine vessels, sporting goods, and electronics encapsulation.
The resins can be employed as gel coatings providing protective coatings for composites and other surfaces.
Applications include biosensors, rheology modifiers, biomaterials, polymerizable surfactants, and polymer matrix composites.
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