Experimental Cold-Cured Nanostructured Epoxy-Based Hybrid Formulations: Properties and Durability Performance

Abstract

Different hybrid epoxy formulations were produced and cold-cured, monitoring the properties development during low temperature curing and aging. All systems were based on silane functionalized bis-phenol A (DGEBA) resins (Part A), cured at ambient temperature with two amine hardeners (Part B). The different components of the formulations were selected on their potential capability to bring about enhancements in the glass transition temperature. The durability of the produced hybrids was probed in comparison to the corresponding neat epoxies by monitoring changes in glass transition temperature (Tg) and flexural mechanical properties after exposure to different levels of humidity and immersion in water and at temperatures slightly higher than the local ambient temperature, in order to simulate the conditions encountered during summer seasons in very humid environments. The thermal degradation resistance of the hybrid systems was also evaluated by thermogravimetric analysis.

Recent Advances and Trends of Nanofilled/Nanostructured Epoxies

“…These systems gained a large success due to their outstanding synergistic properties derived from the beneficial combination of nanosized phases into a bulk epoxy, differing in chemical composition, physical properties, and morphology of the final phases. They can find an advantageous application, for instance, in the field of “cold-cured” adhesives, i.e., those able to set and harden at ambient temperature, due to a marked improvement in properties, in particular the glass transition temperature and durability [ 67 , 68 ].…”

“…The organic–inorganic nanostructured epoxy-silica hybrids are produced employing the hydrolysis–condensation technology typical of ceramic materials. In these nanosystems, the inorganic phase is composed of siloxane nanodomains, i.e., nanometric silica with hydroxyl groups produced by the sol-gel method concurrently to the cross-linking reactions of the organic (epoxy) phase [ 68 ]. It is then possible to obtain the inorganic nanophase and organic network interconnected at a nano-scale level, able to achieve exceptional performance and capabilities, by appropriately controlling the kinetics of the respective reactions.…”

“…The extraordinary chemical and physical properties of a wide variety of experimental nano-epoxies enable a wide range of applications, varying from coatings to structural adhesives, from FRP matrix to electrical/electronic components. Epoxy nanocomposites have found advantageous application in many industrial fields [ 59 , 120 ] such as aerospace [ 114 ], aircraft [ 119 ], automotive [ 33 , 110 ], buildings [ 18 , 67 , 145 , 146 ], electronic devices [ 17 , 86 , 99 , 128 ], sensors [ 90 , 110 , 115 , 127 , 144 ] (even for biomedical applications), anti-static materials [ 9 ], abrasive tools [ 103 ], anti-corrosive coatings (for example in marine environment [ 147 ] or pipes [ 10 ]), and structural applications [ 29 , 68 , 109 ] with self-sensing properties [ 127 ]. Often, the improved properties allow an efficient usage for multifunctional purposes [ 27 , 69 , 148 ].…”

Kinetic features of polymerization of epoxy resin modified by silicon‐containing additives and mineral fillers

“…We hope that the new results of this article expand the investigations of epoxy binder polymerization and may be useful to develop the perspective composites based on epoxy resin with improved characteristics. [45][46][47][48][49] ORCID Sergey E. Savotchenko https://orcid.org/0000-0002-7158-9145…”

State-of-the-Art Polymer Science and Technology in Italy

“…The monitoring of the properties' development of different hybrid epoxy formulations, during low temperature curing and aging, was carried out by Frigione and co-workers [12]. The durability of the produced hybrids was probed in comparison to the corresponding neat epoxies by glass transition temperature (T g ) measurements.…”