Ionic liquid‐functionalized reinforcements in epoxy‐based composites: A systematic review

Abstract

Several high‐performance reinforcements may be used in epoxy‐based composites. These commonly undergo chemical and/or physical treatments to enhance their interfacial interactions with polymer matrices. One recent technology comprises the use of ionic liquids (IL) as compatibilizers. This strategy may result in the development of composite materials with greater performance or multifunctional characteristics. Herein, an overview in the area of IL‐modified reinforcements and their effect on epoxy‐based composites is presented. The PRISMA protocol was followed for the review, and the focus of these studies was on the modification of carbon nanotubes, followed by graphene/graphite nanoplatelets and bio‐fillers. The most used IL were those based on imidazolium cation, especially 1‐butyl‐3‐methylimidazolium chloride. In most cases, when IL are used, the reinforcement displays stronger interactions with the epoxy matrix, depending the treatment route employed. Improved interfacial interactions are cited as the main reason for the improvement in the composite mechanical and thermal performances. It was also found that strategies for using low IL content, or routes that enable recovery of the salts after fiber/particle treatment, are still required, as well as the study of the influence of different amounts/types of IL on the structure of fillers and their relationships with the composite properties.

Preparation and properties of the aramid pulp/nitrile butadiene rubber composites with compatibilization of ionic liquids

“…Ionic liquids (ILs) are normally defined as compounds composed entirely of ions with melting point below 100 C. [21,22] An IL consists of an organic cation and an organic or inorganic anion, and is well known for its low vapor pressure, non-flammability, good thermal and chemical stability [23][24][25][26] and flexible structure design. [27] So far, ILs have been widely applied in the fields of analytical chemistry, [28,29] electrochemistry, [30][31][32] polymerization [33,34] and gas absorption/separation.…”

Imidazolium Ionic Liquids as Compatibilizer Agents for Microcrystalline Cellulose/Epoxy Composites

“…Indeed, a better dispersion of fillers contributes to the enhancement of physical-mechanical properties of composites [ 20 , 21 ]. There are several chemicals for the improvement of interaction of fillers with epoxy resin that use chemical reagents, such as hydrochloric acid, nitric acid, sulfuric acid, acetone, tetrahydrofuran, thionyl chloride, and ethylenediamine, aiming to insert compatible groups on the filler surface [ 9 , 22 ].…”

Effect of the Simultaneous Addition of Polycaprolactone and Carbon Nanotubes on the Mechanical, Electrical, and Adhesive Properties of Epoxy Resins Cured with Ionic Liquids

“…They have also been reported as effective curing agents in several epoxy/thermoplastic systems, such as epoxy/poly(2,6-dimethyl-1,4-phenylen ether) (PPE) [ 53 ], epoxy/polyetherimide (PEI) [ 54 ], and epoxy/poly(ε-caprolactone) [ 45 ], which we included in our previous work. Furthermore, ILs have been used as dispersing agents in CNT-filled thermoplastic [ 55 , 56 , 57 ] and thermoset [ 58 , 59 , 60 , 61 ] NCs.…”