An analysis on the effect of silica in improving the thermal and erosion properties of carbon epoxy composite

Epoxy is an important class of thermosetting polymers that has stimulated considerable research interest since its invention in ۱۹۳۸ owing to its versatility in industrial applications, such as raw materials of surface coatings, adhesives, circuit boards, insulators, packaging matrices and encapsulants of electrical appliances and matrix resin for high-performance fiber-reinforced composites in the transportation sector etc. Several unique properties of cured epoxy resin, such as excellent mechanical and chemical resistance, superior adhesion strength, enhanced durability, extended flame retardancy etc. are achieved due to instability of epoxide rings via reaction with aliphatic or aromatic amines, polyamides, polycarboxylic acids, polyphenols, polysulfides, and anhydrides. The present study aims to improve the mechanical properties of epoxy composite by incorporating supported ionic liquid silica (IL-silica). The IL-silica not only showed improved interfacial interaction and reinforcement, but also served as cure agent of epoxy composites. The differential scanning calorimetry analysis revealed that epoxy composites could be successfully cured with IL-silica without any routine curing agents. IL-silica/epoxy composites presented higher mechanical and thermal properties compared with epoxy composite containing un-functionalized silica (u-silica). The dynamic mechanical analysis showed that the storage modulus of composites significantly increased with the addition of IL-silica in comparison to that with added u-silica, as well as the variation of Tg parameter. The incorporation of IL-silica simultaneously enhanced the tensile strength, toughness, and thermal stability of the epoxy composites. The considerable improvements in mechanical and thermal properties are ascribed to the improved dispersion of IL-silica and the enhanced interfacial interactions between epoxy matrix and IL-silica by strong covalent bonding, which results in an effective load transfer.

کلیدواژه ها:

Epoxy ، Glass transition temperature ، Thermal stability ، Silica