Glass fiber polyester matrix composite

Fig. 7.3. Normalized impact toughness of glass fiber-polyester matrix composites with different fiber coatings (O) silicone vacuum fluid (SVF) Dow Coming 200 Fluid of viscosity 10 cP (A) Dow Corning 200 Fluid of viscosity 10 cP. After Sung et al. (1977).

Khalil et at [36] studied the combination of oil palm fiber and glass fiber as hybrid composite in polyester matrix. Hybrid laminate composites with different weight ratio were prepared to study the hybrid effect of glass and EFB fibers on the physical and mechanical properties of the composites. Generally, the hybrid composites showed better properties as compared to EFB/polyester composites without glass fiber. 

We will see in Section 5.4.2 that the elastic modulus of a unidirectional, continuous-fiber-reinforced composite depends on whether the composite is tested along the direction of fiber orientation (parallel) or normal to the fiber direction (transverse). In fact, the elastic modulus parallel to the fibers, Ei, is given by Eq. (1.62), whereas the transverse modulus, 2, is given by Eq. (1.63). Consider a composite material that consists of 40% (by volume) continuous, uniaxially aligned, glass fibers (Ef =16 GPa) in a polyester matrix (Em = 3 GPa). 

The resin matrix can be either thermosetting or thermoplastic. Thermosetting resins such as epoxy, polyimide, polyester, and phenolic are used in applications where physical properties are important. Polyester and epoxy composites make up the bulk of the thermoset composite market. Of these two, polyesters dominate by far. Reinforced with glass fiber, these are known as fiberglass-reinforced plastics (FRPs). FRPs are molded by layup and spray-up methods or by compression molding either a preform or sheet molding compound (SMC). 

The matrix resins for foamed composites include rigid pol)ruretha-nes, unsaturated polyesters, vinyl esters, and their hybrid resins, such as, unsaturated polyester-urethane hybrid resins and vinyl ester-urethane hybrid resins. The reinforcing fibers include glass fibers, carbon fibers, and organic fibers such as polyamide fiber (Kevlar, DuPont), polyamide-... 

It is well accepted that the good properties of the isotactic polypropylene as an engineering polymer matrix in thermoplastic composite materials and engineering blends are seriously affected by the inability of this polymer to develop an adequate level of interfacial interaction with polar components such as mineral fillers (calcium carbonate) and reinforcements (talc, mica, wollastonite), synthetic reinforcements (glass fibers, carbon fibers, and nanotubes), or engineering polymers such as polyamide, aliphatic polyesters, and so on. 

Example 2.2 Unsaturated polyester resins, which are used as the matrix component of glass-fiber composites, may be obtained by the copolymerization of maleic anhydride and diethylene glycol. The low-molecular-weight product is soluble in styrene. Describe, with the aid of equations, the possible structures of the prepolymer and that of the polymer resulting from benzoyl peroxide-initiated polymerization of a solution of the prepolymer in styrene. 

In motor vehicles, long glass fiber-reinforced parts with a matrix consisting of unsaturated polyester resin (SMC/sheet molding compounds) are used for example in front-ends, radiator grills, or bumper (frames). After utilization, they are discarded as waste by workshops or as part of the plastic and composite material share in used vehicles. 

Polymer composite materials are substances that have a polymer matrix with reinforcing fibers. Glass-fiber-reinforced polyesters are used for boat hulls and car body panels. Graphite fiber-epoxy composites are used in fishing rods and tennis racquets. 

Other sources of reinforcement are fibers like those of carbon and metal. Fibers can add rigidity and help prevent crack propagation. A common composite is fiberglass, which consists of small glass fibers embedded within a polymeric material that is typically an epoxy or polyester [11]. Epoxy resin is used as a structural matrix in the aerospace industry. It is also used as glue. 

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