Renewable highly biobased polybenzoxazine thermosets for composite applications
Inventors
Palmese, Giuseppe R. • Yadav, Santosh K. • LaScala, John J.
Assignees
Drexel University • United States Department of the Army
Publication Number
US-11958841-B2
Publication Date
2024-04-16
Expiration Date
2038-08-21
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Abstract
Benzoxazine compounds, methods of making them, polymers made therefrom and methods of polymerizing the benzoxazines. These renewable benzoxazine monomers and polymers that utilize the variety of building blocks found in renewable plant biomass, demonstrate excellent processability and large temperature windows for processing of resin systems.
Core Innovation
The invention relates to a series of renewable benzoxazine monomers and polymers derived from renewable plant biomass. These benzoxazine compounds demonstrate excellent processability and have large temperature windows for processing resin systems, allowing for tunable properties by combining different bio-based building blocks. The polymers formed from these monomers offer improved processability and properties, aiming to replace some petroleum-based polymers with highly bio-derived alternatives.
The problem solved by this invention centers on the challenges posed by the reliance on petroleum-derived benzoxazine monomers and polymers, which face issues of supply, cost, limited types of chemical structures, and environmental concerns. Traditional polybenzoxazines, while possessing advantageous thermal and mechanical properties, are largely dependent on non-renewable fossil fuels. This invention addresses the need for renewable alternatives by developing benzoxazine monomers and polymers that utilize the variety of building blocks found in renewable plant biomass, thereby overcoming the limitations of petroleum-derived materials.
Claims Coverage
The patent contains 10 independent claims covering benzoxazine compounds, methods for their formation, and polymers derived therefrom, featuring multiple inventive structural and compositional aspects.
Benzoxazine compounds with specified substituents
The claims include benzoxazine compounds of Formula (I) and Formula (III) with R1 and R2 groups independently selected from hydrogen, alkyl, alkenyl, alkoxy groups of 1-4 carbon atoms, and —C(═O)H; R3 may be hydrogen or a defined group having Formula (II) with substituents R4 and R5 with specified optional substitutions and restrictions, ensuring R4 and R5 cannot both be hydrogen. Formula (III) includes additional defined substituents R7, R8, and R9 with optional substitutions.
Symmetry and bonding positions of substituents on benzoxazine rings
The benzoxazine compounds may be symmetrical where R1 and R2 of Formula (I) are identical to those of Formula (II). Substituents R1 and R2 are bonded at specific positions, such as the 6 and 8 positions or 5 and 8 positions on the benzoxazine ring; at least one of R1 or R2 is not hydrogen.
Preparation method by reacting specific compounds
A method of forming benzoxazine compounds by reacting a furfurylamine compound (defined by Formula (IV) or (V)), a formaldehyde compound (formaldehyde or paraformaldehyde), and a phenol compound selected from phenol, bisphenol A, bisguaiacol, vanillin, carvacrol, and eugenol, optionally employing an inert organic solvent and heating the mixture at 60-85° C.
Polymers formed by ring-opening polymerization
Polymers formed by ring opening polymerization of benzoxazine compounds of Formula (I) or (III) optionally including epoxidation with diepoxides or epoxide compounds such as bisphenol A diglycidyl ether (DGEBA) and others, resulting in polymers comprising repeating units defined by specific formulae (VII) and (VIII), with detailed substituent structures.
Polymer compositions with additives
Polymer compositions comprising the described polymers and further including additives like fibers, clays, silicates, fillers, pigments (titanium dioxide, iron oxides, carbon black), corrosion inhibitors (zinc phosphate), flow additives, stabilizers, flame retardants, and other functional components.
The claims comprehensively cover the chemical structure of novel renewable benzoxazine compounds with specified substituents and symmetries, methods for their synthesis using defined reactants, polymers derived by ring-opening polymerization optionally combined with epoxy curing agents, and polymer compositions including functional additives. The disclosed features detail chemical compositions, synthesis conditions, polymer structures, and additives to achieve renewable, processable, and functional thermoset materials.
Stated Advantages
The renewable benzoxazine polymers demonstrate improved processability compared to conventional materials.
The benzoxazine monomers and polymers exhibit large temperature windows for processing, offering flexibility in resin system processing.
The polymers have tunable properties enabling customization for various applications.
The invention provides alternatives to petroleum-based polymers, addressing supply and environmental concerns.
Documented Applications
Use as tunable-property biobased resin systems for composite applications.
Preparation of molding compositions for coatings on electronic devices such as semiconductors or circuit boards.
Formulation of polymer compositions with additives for use in fibers, fillers, pigments, corrosion inhibitors, flame retardants, and other functional components suitable for high-performance materials.
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