FYA de Xiaoli Xu titulado: “Bio-based Flame-retardant Epoxy Resins for Adhesives: Synthesis, Characterization and Properties”- 18 de abril de 2024.


Epoxy resin adhesive mainly consists of two parts: epoxy resin and curing agent. The currently commonly used ones are epoxy thermosetting resins derived from fossil resources, which have a permanent cross-linked structure and can only be used once, cannot be further processed, and cannot be recycled. Its large-scale application has led to problems such as resource crisis, environmental pollution, and resource waste. Therefore, this study mainly designs epoxy resins and curing agents using renewable resources as raw materials to develop sustainable thermosetting epoxy resins.
This study focuses on the petroleum based epoxy resin mainly used in the adhesive system. The bio-based epoxy resin glycerol triethyl ether (GTE) partially replaces the bisphenol A type epoxy resin (E51), aiming to increase the proportion of bio-based products in the epoxy resin adhesive. Studied and compared the changes in epoxy value of resins with the addition of 0, 10%, 30%, 50%, 70%, 90%, and 100% GTE. Using commonly used DDM as a curing agent, studied the curing kinetics through DSC, and compared the changes in tensile strength, peel strength, thermal degradation, glass transition temperature, and storage modulus. When GTE reaches 50%, the tensile strength and bonding strength reached 85.7 MPa and 8.9 MPa, increasing by 35% and 118%, indicating that epoxy resins with partial bio-based content can be suitable.
For bio-based curing agents, research epoxy systems with higher bio-based content. Vanillin was used as the raw material, through aldehyde amine condensation reaction with DDM, the raw material ratio at 2:1 or 1:1. Two bio-based curing agents VAD and VADD containing dynamic imine bonds and different crosslinking sites were synthesized.
A commercial bio-based epoxy resin GTE was directly cured using VAD to prepare bio-based epoxy glass VAD-GTE based on dynamic imine bonds. The curing kinetics process was studied by DSC. Indicate that when R is 0.7, completely cure; When R is 0.9, the tensile strength reaches 69.5 MPa, which is similar to the performance of DDM cured GTE. The dynamic thermal mechanical properties were studied through DMA, and the Tg and loss of VAD-GTE were lower than those of DDM-GTE. However, the storage modulus E’ at 30 ℃ is relatively high, which is directly related to the crosslinking density and segment stiffness of VAD. Verified the chemical solvent resistance of VAD-GTE undergo slight dissolution in highly polar DMSO and DMF solvents.
After a year of work, epoxy resins and curing agents using renewable resources as raw materials, and developed epoxy resin adhesives with partial bio-based content. Bio-based GTE can replace 50% of E51 in practical applications. A bio-based curing agent with imine bond structure was synthesized based on vanillin, and the properties after GTE curing were studied. The introduction of Schiff bonds achieved high-performance
bio-based epoxy resin, and endowed them with processability and recyclability, opening up a new path for the preparation and application of bio-based epoxy.
Keywords: bio-based epoxy resin; flame retardancy; reprocess; adhesive

La asistencia será remota:

Tema de la reunión: Evaluación del primer año para la Sra. Xiaoli Xu
Hora: 18 de abril de 2024, de 14:00 a 17:00 (GMT+02:00) Hora de Europa Central – Madrid

Número de conferencia: 395-014-525