Fabrication and mechanical characterization of glass fiber reinforced UV-cured composites from epoxidized vegetable oils

Abstract

Novel fiberglass-reinforced composites were fabricated by the ultraviolet and visible (solar) irradiation of epoxidized vegetable oils in the presence of onium salt cationic photoinitiators. A variety of layup techniques and experimental conditions were explored to optimize composite fabrication. It was demonstrated that composites prepared by wet layup techniques containing up to five plies of glass cloth could be cured by a direct, 25-min exposure to solar irradiation. A series of composite samples were prepared using mixtures of epoxidized vegetable oils and synthetic epoxy resins, and their mechanical properties were evaluated. Based on these measurements, it may be concluded that photochemical routes to the fabrication of composites derived from epoxidized vegetable oils provide a simple, direct, and inexpensive route to the fabrication of composites with many potential low-performance applications.

Effects of catalysts and post-curing conditions in the polymer network of epoxy and phenolic resins: Preliminary results

“…The hydrophobic nature of ELO is exhibited by the less weight gain when the samples containing ELO were immersed in water for a longer time than those consisting of epoxies only. The samples post-cured at 100 o C darkened considerably, and suggest that oxidative degradation occurs at this temperature in the unstabilized ELO [8].…”

“…Moreover, heating up to 150 ºC weakened the material and this is in line with the work of Crivello et al [8].…”

Polymers From Biological Oils

“…However, epoxidized oils can be directly polymerized to give materials of different hardness [8,9].Again, super acids are good catalysts for cationic polymerization of internal epoxides. While terminal epoxides are traditionally reacted with amines, this reaction does not proceed with internal epoxy groups.…”

“…Epoxidized linseed oil gives somewhat harder materials with glass transition (T g ) in the range 40-60 o C, and of higher tensile strength, but not sufficient for a binder for strong fiber reinforced composites [8].…”

Fully bio-based aliphatic thermoset polyesters via self-catalyzed self-condensation of multifunctional epoxy monomers directly extracted from natural sources

“…Epoxidized vegetable oils are produced in large volumes and have applications ranging from plasticizing additives in PVC where they also act as acid quenchers, stabilizing the PVC toward thermal degradation, 16 to cationically polymerizable UV resins. 17,18 Epoxidized vegetable oils are also used as precursors for other types of thermoset resins such as acrylates, e.g., acrylated epoxidized soybean oil that can be freeradically polymerized to form thermoset structures. 19,20 One limitation with thermosets based on epoxidized vegetable oils is that the pure aliphatic structure normally gives rather soft materials, i.e., it is difficult to obtain a high glass transition temperature, T g , of the final crosslinked system.…”