Trade-offs Between Limonene & Geraniol-Based Reprocessable and Non-Reprocessable Epoxy Thermosets: Role of Aliphatic Diamines in Polymer Networks Design.
Category
Sciences and Technology
Department
Polymer Chemistry
Student Status
Graduate
Research Advisor
Dr. Ram Gupta
Document Type
Event
Location
Student Center Ballroom
Start Date
10-4-2025 2:00 PM
End Date
10-4-2025 4:00 PM
Description
The growing demand for sustainable materials, driven by environmental concerns and the rapid depletion of fossil fuels, has garnered significant attention in bio-based thermosets fabrication. Petroleum-derived thermosetting polymers can be replaced with renewable alternatives such as limonene and geraniol-derived epoxy prepolymers. The present study focuses on the synthesis and characterization of limonene and geraniol-based epoxy prepolymers over a two-step process and their thermally crosslinked thermosets using different aliphatic diamines. Incorporating cystamine, a disulfide-containing diamine, introduced a covalent adaptable network via disulfide metathesis, achieving a reprocessable thermoset with self-healing capabilities, recyclability, and extended lifespan. In contrast, traditional aliphatic diamines produced a permanently crosslinked thermoset with superior mechanical strength, thermal stability, and chemical resistance, ideal for high-performance applications requiring durability with maximum tensile strength of 11.62 MPa and 17.9 MPa for limonene and geraniol derived epoxy thermoset, respectively. Differential scanning calorimetry (DSC) elucidated the curing kinetics and crosslinking behavior, while thermogravimetric analysis (TGA) confirmed excellent thermal stability. Dynamic mechanical analysis (DMA) and tensile testing also demonstrated desirable mechanical properties. The glass transition temperature (Tg) of the limonene- and geraniol-derived malleable thermosets was determined by dynamic mechanical analysis (DMA) at 18C and 25℃, respectively. Above these temperatures, the malleable thermosets exhibited dynamic behavior facilitated by disulfide bond exchange. In addition, the developed materials displayed maximum tensile strengths of 3.1 MPa and 3.66 MPa, highlighting their mechanical robustness and potential for reprocessable applications.
Trade-offs Between Limonene & Geraniol-Based Reprocessable and Non-Reprocessable Epoxy Thermosets: Role of Aliphatic Diamines in Polymer Networks Design.
Student Center Ballroom
The growing demand for sustainable materials, driven by environmental concerns and the rapid depletion of fossil fuels, has garnered significant attention in bio-based thermosets fabrication. Petroleum-derived thermosetting polymers can be replaced with renewable alternatives such as limonene and geraniol-derived epoxy prepolymers. The present study focuses on the synthesis and characterization of limonene and geraniol-based epoxy prepolymers over a two-step process and their thermally crosslinked thermosets using different aliphatic diamines. Incorporating cystamine, a disulfide-containing diamine, introduced a covalent adaptable network via disulfide metathesis, achieving a reprocessable thermoset with self-healing capabilities, recyclability, and extended lifespan. In contrast, traditional aliphatic diamines produced a permanently crosslinked thermoset with superior mechanical strength, thermal stability, and chemical resistance, ideal for high-performance applications requiring durability with maximum tensile strength of 11.62 MPa and 17.9 MPa for limonene and geraniol derived epoxy thermoset, respectively. Differential scanning calorimetry (DSC) elucidated the curing kinetics and crosslinking behavior, while thermogravimetric analysis (TGA) confirmed excellent thermal stability. Dynamic mechanical analysis (DMA) and tensile testing also demonstrated desirable mechanical properties. The glass transition temperature (Tg) of the limonene- and geraniol-derived malleable thermosets was determined by dynamic mechanical analysis (DMA) at 18C and 25℃, respectively. Above these temperatures, the malleable thermosets exhibited dynamic behavior facilitated by disulfide bond exchange. In addition, the developed materials displayed maximum tensile strengths of 3.1 MPa and 3.66 MPa, highlighting their mechanical robustness and potential for reprocessable applications.
