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-11208420-B2
Publication Date
2021-12-28
Expiration Date
2037-11-16
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
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/crosslinker/reactive diluent. Additionally, the novel resin systems may be partially to fully biobased, 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 describes a method for producing a blended resin system through a one-pot, two-step reaction process. The method includes first reacting an organic compound containing at least one hydroxy group with methacrylic anhydride to produce a (meth)acrylic ester and (meth)acrylic acid. The second step involves reacting the resulting product with an organic compound containing at least one epoxy group to form a further reaction product. Optionally, this product can be blended with up to about 75 weight percent of a reactive diluent to produce a curable resin.
The problem addressed by this invention lies in the limitations of current vinyl ester resin systems, which are primarily petroleum-based and often require reactive diluents such as styrene to reduce viscosity for processing. These reactive diluents pose environmental and health concerns due to being hazardous air pollutants and volatile organic compounds. Additionally, petroleum dependency contributes to cost volatility and environmental impact. Thus, there is a need for bio-based vinyl ester resins with improved processability, acceptable toughness, and reduced reliance on harmful reactive diluents.
The invention utilizes bio-based anhydrosugars, specifically dihydroxy anhydrosugars like isosorbide, as principal components to produce methacrylated monomers with relatively low molecular weight and rigid bicyclic core structures. This structure aids in lowering the viscosity of the resin system, thereby reducing or eliminating the need for hazardous reactive diluents while achieving desirable toughness and processability. The method further advantages by using the by-product methacrylic acid in a subsequent step, reacting it with glycidyl ethers to form methacrylated epoxy compounds, thus eliminating the need for separation and purification of reaction by-products.
Claims Coverage
The patent contains three independent claims encompassing methods for producing curable resins using one-pot, two-step reactions involving hydroxy group containing organic compounds and epoxy-containing compounds, and optionally curing the resins.
One-pot, two-step reaction method with specific molar ratios using isosorbide and (meth)acrylic anhydride
This method involves reacting isosorbide with (meth)acrylic anhydride at a molar ratio from about 1:1.5 to about 1:2.5 to produce a reaction product containing (meth)acrylic ester and acid, then reacting with an organic compound containing at least one epoxy group, and optionally blending with up to about 75 wt % reactive diluent to produce curable resin.
Use of glycidyl ether or epoxidized oils as the organic compound containing epoxy groups
The method employs organic compounds containing epoxy groups selected from glycidyl ethers including diglycidyl ether of bisphenol A and its oligomers, as well as epoxidized oils, cardanol, and ricinoleic acid compounds for reacting with the reaction product from the first step.
Carrying out reactions in presence of catalysts under specific conditions
The method conducts step i) in the presence of a basic catalyst such as 4-dimethylaminopyridine and step ii) at temperatures of 25° C. to about 100° C. with catalysts including chromium complexes, triphenyl antimony/phosphine mixtures, and others under acidic conditions for effective reaction progress.
Optionally curing the curable resin by free-radical curing or epoxy polymerization methods
Following resin production, the method includes optional curing steps by free-radical curing and/or sequential polymerization such as epoxy homopolymerization, epoxy-amine polymerization, or epoxy-anhydride polymerization, to form interpenetrating polymer networks enhancing resin properties.
The claims collectively emphasize a novel one-pot, two-step synthetic approach using bio-based hydroxy compounds and epoxy-containing compounds with controlled molar ratios and catalyst usage to produce curable blends exhibiting beneficial viscosity and thermal properties. The method includes optional curing steps to obtain high-performance, environmentally favorable resins with improved processability and reduced reliance on hazardous diluents.
Stated Advantages
The one-pot, two-step reaction eliminates the need for separation and purification, reducing manufacturing costs and waste disposal.
The use of bio-based anhydrosugars and partial to full biobased resin systems promotes global sustainability and reduces dependency on petroleum resources.
The method produces resin systems with controlled ratios and lower viscosity, improving ease of processing and reducing or eliminating the need for hazardous reactive diluents.
Free radically polymerized resins exhibit properties that meet or exceed those of petroleum-derived counterparts, including high glass transition temperatures and desirable mechanical stiffness and toughness.
Documented Applications
Use of the resin systems as thermosetting polymers suitable for high performance applications including adhesives, coatings, composite matrices, and polymer matrix composites for military, automotive, recreational, and marine uses.
Manufacture of automotive products, aircraft airframe skins, composite armor, marine vessels, sporting goods, and industrial adhesives involving infrastructure and electronics encapsulation.
Use in thermosetting liquid molding resin formulations and gel coatings to provide protective layers for composites and other surfaces.
Interested in licensing this patent?