Aramid fiber-epoxy matrix composite

Silicon (100) orientation 0.28 COMPOSITE MATERIALS Aramid fibers-epoxy matrix Vf = 0.6) 0.34... 

Fig. 5.21. Surface amine concenlralion (O) of aramid fiber and ILSS ( ) of epoxy matrix composites as a function of ammonia plasma treatment time. After Brown et al. (1991).

Carbon, and Aramid Fiber-Reinforced Epoxy-Matrix Composites in Longitudinal and Transverse Directions"... 

Composite In polymer technology a combination of a polymeric matrix and a reinforcing fiber with properties that the component materials do not have. The most common matrix resins are unsaturated thermosetting polyesters and epoxies, and reinforcing fibers are glass, carbon, and aramid fibers. The reinforcing fibers may be continuous or discontinuous. Some matrix resins are thermoplastics. 

Addition poly(imide) oligomers are used as matrix resins for high performance composites based on glass-, carbon- and aramide fibers. The world wide market for advanced composites and adhesives was about 70 million in 1990. This amounted to approximately 30-40 million in resin sales. Currently, epoxy resins constitute over 90% of the matrix resin materials in advanced composites. The remaining 10% are unsaturated polyester and vinylester for the low temperature applications and cyanate esters and addition poly(imides) for high temperatures. More recently thermoplastics have become important and materials such as polyimides and poly(arylene ether) are becoming more competitive with addition polyimides. 

Kevlar 29 and versions thereof (K 129 and Kl j.) are also used extensively in lightweight body armor as well as composite liners (with vinylester, polyester or epoxy as the matrix). A quick look at the properties of different Kevlar aramid fibers in Table 4.2 shows why K29 is better than K49 for lightweight body armor applications. K29 has a higher strain to failure than K49. That means that the total work of fracture, i.e. the area under the stress-strain curve, is larger for K29 than K49. Hence, the energy absorbed in the fracture process is higher for K29... 

Epon HPT . [Shell] Epoxy matrix resin used for advanced composites with glass, carbon, aramid or b n fibers, high-performance structural laminates and adhesives, preptegs. 

Sydenstricker et al. [38] evaluated the IFSS of sisal fibers, both untreated and subjected to different surface chemical treatments, by SFP tests. The sisal fibers were inserted at a constant 3 mm depth in polyester blocks. The authors found [38] that the values of IFSS that are given in Table 9.1 showing treated sisal fibers, up to a certain level of surface chemical treatment, present better IFSS with polyester as possible composite matrix. It can also be inferred from Table 9.1 that the value for both the untreated and treated fibers are markedly lower when compared to synthetic fibers with polymeric matrix. For instance, Tanaka et al. [40] reported an IFSS of 20 MPa for aramid fiber embedded in epoxy matrix. 

The common commercially available fibers used in composites are fiberglass, graphite (carbon), aramid, polyethylene, boron, silicon carbide, and other ceramics such as silicon nitride, alumina, and alumina silica. Many matrix choices are available, both thermosetting and thermoplastic. Each type has an impact on the processing technique, physical properties, and environmental resistance of the finished composite. The most common resin matrices include polyester, vinyl esters, epoxy, bismaleimides, polyimides, cyanate ester, and triazine. 

The aramid fibers are most often used in composites having polymer matrices common matrix materials are the epoxies and polyesters. Because the fibers are relatively flexible and somewhat ductile, they may be processed by most common textile operations. Typical apphcations of these aramid composites are in balhstic products (bulletproof... 

Cryogenic properties of fibers and composites are given in Table 2. Most fiber-composite properties are governed by anisotropic features originating in the fiber arrangement and anisotropy and fiber-matrix interfacial bond. The fiber-matrix bond is discussed in refs. (36) and (39). In this article, the matrix materials discussed are epoxy resins, poljdmides, and polycarbonates and the fibers glass, carbon, and Kevlar, ie, aramid fibers. 

Janssens, W., Doxsee Jr., L., Verpoest, I. and de Meester, P. (1989). Influence of the fiber-matrix interface on the transverse bending strength of dry and moist aramid-epoxy composites. In Proc. Interfacial Phenomena in Composite Materials 89, (F.R. Jones ed.), Butterworths, London, pp 147-154. 

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