Epoxy as Filler or Matrix for Polymer Composites

Abstract

Epoxy is a widely used polymer because of its ease of processing, high adhesiveness, and high chemical resistance. Epoxy-based composites are commonly used in aerospace, automotive, and marine applications. The epoxy type, function, curing agent, and curing process are discussed in this chapter. Epoxy is used as either a filler or polymer matrix in composite applications. As a filler, the epoxy modification on the fiber is discussed. As a polymer matrix, the epoxy is reinforced by natural and synthetic fibers. The manufacturing process and the fabricated epoxy-based composites’ performance (e.g., mechanical and thermal properties) are investigated. The advantages and disadvantages of epoxy’s function are discussed and summarized. Epoxy modification is an effective approach to improve the composites’ performance.

Experimental Estimation of Energy Absorbed and Impact Strength of Kevlar/Basalt-Epoxy Interwoven Composite Laminate Added with Al2O3 Nanoparticles after High-Velocity Bullet Impact

“…(i) After the high-velocity impact test, the results are as follows: (ii) Te bullet impact test revealed that the bullet pierced smoothly through the composite specimens in all three cases (iii) Delamination, fber-matrix compression damage, matrix cracking, and tensile failure of yarns have been recognized as the primary failure mechanisms under impact load [25] Alumina powder Hardener (iv) Composite failure is due to the high-velocity impact of the projectile, which generates a compression wave through the thickness of the sample and is refected as a tension causing fber delamination or detachment between the lamina layers [39] (v) When the warp and weft threads break in the collision zone, friction between the projectile and target becomes the primary mechanism, continuing to slow the projectile [39] (vi) Te impact area, impact velocity, and residual velocities were predicted using the Image J and Cine viewer software (vii) Adding nanoparticles to composite materials results in astonishing changes in mechanical properties [25] (viii) Te hybrid samples absorb more energy than individual samples [26] (ix) It was found that the afected area of KB3 (10.82 cm 2 ) was larger, i.e., more damaged composite panel; this was because the addition of a higher percentage of alumina powder resulted in a small intermolecular gap resulting in a series of alumina particles in one place causing the epoxy bond to break and lead to brittle nature of the material [32]. (x) As the nanopowder content increases, the impact energy increases, and as the impact energy increases, so does the absorbed energy, so the KB3 (39.34 J) composite sample absorbs more energy than the other two samples, as shown in Figure 14 [20,41] (xi) In the case of KB1, the alumina content is too low (1%), so the distance between the molecules is too small, which does not help to create stronger bonds between the epoxy molecules, so the impact strength is reduced [40] (xii) Te impact damage area is low in KB2 (8.13 cm 2 ) because of the strong polymeric bond, closely packed structure, and the dense nature obtained by adding nanofllers [31,41] (xiii) KB2 (4.28 J/cm 2 ), as shown in Figure 13, gives good impact strength compared to KB1 (2.75 J/cm 2 ) and KB3 (3.63).…”

“…A traditional handloom weaving process is used to hybridize Kevlar and basalt fbers, which, although this is a time-consuming but cost-efective process, can reduce production costs. Due to the attractive mechanical properties, optimum adhesion, strong chemical resistance, and wide range of coatings, epoxy resins are often used in producing polymer-based composites [26].…”

Effects of Phosphorus and Boron Compounds on Thermal Stability and Flame Retardancy Properties of Epoxy Composites

“…Epoxy resins have been widely used as polymeric matrices for the preparation of composites with improved characteristics. The properties of composites depend on the structure of the resins, curing agent, and organic or inorganic fillers [ 4 , 5 , 6 ]. However, cured epoxy resins have high flammability, which reduces their application in areas where flame-resistant polymeric materials are required.…”

Impact of Mendong fiber–epoxy composite interface properties on electric field frequency exposure

“…13,14 The importance of incorporating natural fibers into epoxybased composites lies in their ability to support sustainable and eco-friendly manufacturing practices. 15 With mounting concerns over climate change and its environmental consequences, industries are actively pursuing alternatives to fossil fuel-derived materials. Natural fiber composites offer a promising solution, particularly in applications that can leverage the mechanical characteristics of these fibers effectively.…”

“…The properties of the cured resins are influenced by the specific conditions during the curing process. 15 Curing processes of epoxy can be conducted at an autoclave and oven that use a curing temperature of 120-160 C. 41,42 Microwaves are usually used for the curing process since the curing reaction rate was faster than thermal curing, 43 but it involves high energy and frequency. Utilizing the electric field is simple, and applying low frequency introduces no heat into the system but does not lead to a shortening process.…”