Optimization of the Curing and Post-Curing Conditions for the Manufacturing of Partially Bio-Based Epoxy Resins with Improved Toughness

Abstract

This research deals with the influence of different curing and post-curing temperatures on the mechanical and thermomechanical properties as well as the gel time of an epoxy resin prepared by the reaction of diglycidyl ether of bisphenol A (DGEBA) with an amine hardener and a reactive diluent derived from plants at 31 wt %. The highest performance was obtained for the resins cured at moderate-to-high temperatures, that is, 80 ° C and 90 ° C , which additionally showed a significant reduction in the gel time. This effect was ascribed to the formation of a stronger polymer network by an extended cross-linking process of the polymer chains during the resin manufacturing. Furthermore, post-curing at either 125 ° C or 150 ° C yielded thermosets with higher mechanical strength and, more interestingly, improved toughness, particularly for the samples previously cured at moderate temperatures. In particular, the partially bio-based epoxy resin cured at 80 ° C and post-cured at 150 ° C for 1 h and 30 min, respectively, showed the most balanced performance due to the formation of a more homogeneous cross-linked structure.

Development of Injection-Molded Polylactide Pieces with High Toughness by the Addition of Lactic Acid Oligomer and Characterization of Their Shape Memory Behavior

“…As previously indicated, one of the most widely used strategies to improve toughness in PLA-based formulations is blending with rubber-like polymers such as PCL [58], PBS [29,59], or PBAT [60,61]. In these immiscible blends, the energy absorption is related to presence of finely dispersed rubber-like small polymer droplets embedded in the brittle PLA matrix.…”

The Effect of POSS Type on the Shape Memory Properties of Epoxy-Based Nanocomposites

“…Higher curing temperatures, up to 160 °C, had a 30% negative effect on the degree of curing of the pristine epoxy. The lower degree of curing may be caused by the diffusion limiting stage becoming dominant earlier compared to the original curing process [ 60 ]. Thus, a curing temperature of 100 °C was chosen for all EPOSS compositions.…”

Manufacturing and Characterization of Green Composites with Partially Biobased Epoxy Resin and Flaxseed Flour Wastes

“…The resulting resin-filler mixture was poured into a silicone mold designed with standardized cavities for mechanical characterization and then subjected to a curing cycle in an oven at 80 • C for 1 h. Cured samples were post-cured at 150 • C for 30 min. The optimal curing and post-curing conditions of the partially biobased epoxy resin were selected according to a previous study [53]. Finally, cured samples were demolded from the silicone molds and used for different characterizations.…”