Glass fiber-PEEK composite

Figure 5.25 shows that the glass transition of composites containing carbon fibers may be affected by water uptake. The glass transition of carbon fiber/PEEK composite remains the same under diy and wet conditions. But carbon fiber/epoxy composites may experience a decrease in Tg as high as 77°C depending on the properties of the matrix resin." "... 

The most widely used and least expensive polymer resins are the polyesters and vinyl esters. These matrix materials are used primarily for glass fiber-reinforced composites. A large number of resin formulations provide a wide range of properties for these polymers. The epoxies are more expensive and, in addition to commercial applications, are also used extensively in PMCs for aerospace applications they have better mechanical properties and resistance to moisture than the polyesters and vinyl resins. For high-temperature applications, polyimide resins are employed their continuous-use, upper-temperature limit is approximately 230°C (450 F). Finally, high-temperature thermoplastic resins offer the potential to be used in future aerospace applications such materials include polyetheretherketone (PEEK), poly(phenylene sulfide) (PPS), and polyetherimide (PEI). 

Fig. 5. Interlaminar fracture toughness, for a number of thermosetting and thermoplastic composites (36,37). Open white bars represent glass-fiber composites shaded bars are for carbon fibers. The materials are A, polyester (unidirectional) B, vinyl ester (CSM = chopped strand mat) C, epoxy (R/BR1424) D, epoxy (T300/914) E, PPS F, PES and G, PEEK. To convert J/m to fdbf/in. multiply by 2100.

Fig. 19. Inlerfacial shear strengths of various fiber/matrix composites as a function of the work of adhesion as determined by IGC. 1, glass fiber-poly (ethylene) 2, carbon fiber-epoxy B 3, carbon fiber-epoxy A and 4, carbon fiber-PEEK. Redrawn from ref. [102].

Fig. 6.9. Normalized fracture toughness, (Kc - AKQ)/K. of short glass fiber-thermoplastics injection molded composites as a function of reinforcing effectiveness parameter, ft (O) polyetheretherketone (PEEK) matrix (K = 6.5 MPa m) (A) polytetrafluoroethylene (PTFE) matrix (K = 1.9 MPaym).

Carbon and glass-fiber reinforced PEEK has been used with advanced plastics technology in the redesigning of the helicopter blades profile, improving aerodynamic properties, and reducing overall weight [37]. The use of PEEK composites in the RAF Linx helicopter enabled it to break the world helicopter speed record. 

Sumer, M., Unal, H., and Mimaroglu, A. (2008). Evaluation of tribological behaviour of PEEK and glass fiber reinforced PEEK composite under dry sliding and water lubricated conditions. Wear265(7 S), 1061-1065. 

Figure 4.4 Comparison of (a) stiffness, (b) strength, and (c) fracture toughness for metals, technical ceramics, composites, and fiber-reinforced plastics with respect to those of bone. CF, carbon fiber GF, glass fiber PA 12, polyamide 12 PC, polycarbonate PE, polyethylene PEEK, poly ether ether ketone PLGA, poly(L-lactic-co-glycolic acid) PLEA, poly(L-lactic acid) PP, polypropylene PSU, polysulfone PTFE, polytetrafluoroethylene PUR, polyurethane.

Engineering thermoplastics have also been used ia preimpregaated coastmctioas. The thermoplastic is thoroughly dispersed as a coatiauous phase ia glass, other resias, carboa fibers (qv), or other reinforcement. Articles can be produced from these constmctions usiag thermoforming techaiques. For example, the aerospace iadustry uses polyetheretherketoae (PEEK) ia wovea carboa-fiber tapes (26). Experimental uses of other composite coastmctioas have beea reported (27) (see also Composite materials, polymer-matrix). 

The model PBZT/ABPBI molecular composite system is limited since the rod and the matrix do not possess glass transition temperatures for subsequent post form consolidation. In an effort to improve the processability for molecular composites, thermoplastics were used as the host matrix. Processing from acidic solvents requires the thermoplastic host to be soluble and stable in meth-anesulfonic add. Thermoplastic matrices were investigated including both amorphous and semicrystalline nylons [71,72], polyphenylquinoxaline (PPQ) [73] and polyetheretherketone (PEEK) [74], Table 5 shows the mechanical properties obtained for various processed PBZT thermoplastic molecular composite systems. As an example, the PBZT/Nylon systems showed 50-300% improvement over uniaxially aligned chopped fiber composite of comparable compositions. However, the thermally-induced phase separation during consol-... 

Another important application of thermoplastic fibers such as poly ether ether ketone (PEEK), Poly etherimide(PEI), and VectranM andHS (Vectranis the trade mark of Hoechst liquid crystalline polymer) is in making thermoplastic matrix composites. Commingled yams of the reinforcement and matrix such as quartz/PEEK, glass/PEI, Vectran HS/M are used to make the composites wherein the matrix yarn fuses to form the continuous phase of the composite. 

Special considerations trace metals such as Co, Cu, Ni radically reduce thermal stability some carbon fibers cause degradation due to the surface impurities some types of glass reduce stability of poly imide polyimide is used as modifier of PEEK/carbon fiber composite " ... 

PEEK derivatives have significant commercial utility as plastics, especially as molded articles and as composites with glass, carbon, and Kevlar fibers for a variety of structural applications, including the aerospace and general engineering industries. PEEK also finds applications as extruded rods and profiles for manufacture of bushings, seals, etc. 

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