Polymer Matrix Composites PMCs

Description and general properties. Polymer matrix composites (PMCs) consist of a pol)oner matrix or resin reinforced with glass fibers and to a lesser extent carbon, boron and pol)r-aramide fibers. The resin systems used to manufacture advanced composites are of two basic types thermosets and thermoplastics (see Chapter 11). Thermosetting resins predominate today, while thermoplastics have only a minor role in advanced-composite manufacture. Thermoset resins require the addition of a curing agent or hardener and impregnation onto 

Processing. Numerous processes are used for manufacturing PMCs and they are briefly listed in Table 18.3. 

---

Most fiber-matrix composites (FMCs) are named according to the type of matrix involved. Metal-matrix composites (MMCs), ceramic-matrix composites (CMCs), and polymer-matrix composites (PMCs) have completely different structures and completely different applications. Oftentimes the temperatnre at which the composite mnst operate dictates which type of matrix material is to be nsed. The maximum operating temperatures of the three types of FMCs are listed in Table 1.27. 

Nanolithography Polymer-matrix composites (PMC) Scanning/atomic force microscopy (SFM/AFM) Thermal diffusivity... 

Data regarding the effects of cyclic loading and creep on the life of brittle matrix composites are limited. The concepts to be developed thus draw upon knowledge and experience gained with other composite systems, such as metal matrix composites (MMCs) and polymer matrix composites (PMCs). The overall philosophy is depicted in Fig. 1.7. 

CMCs with 2-D fiber architecture are susceptible to interlaminar cracking in various component configurations (Fig. 1.38). In such cases, as the crack extends through the component, conditions range from Mode I to Mode II. Tests and analyses are needed that relate to these issues. Most experience has been gained from polymer matrix composites (PMCs).99 The major issue is the manner whereby the interlaminar (transverse) cracks interact with the fibers. In principle, it is possible to conduct tests in which the cracks do not interact. In practice, such interactions always occur in CMCs, as the crack front meanders and crosses over inclined fibers.100,101 These interactions dominate... 

Comparison of several techniques (namely Fourier transform infrared spectroscopy (FTIR), simultaneous thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) and ultrasonic spectroscopy) for assessing the residual physical and mechanical characteristics of polymer matrix composites (PMCs) exposed to excessive thermal loads showed the measured power spectra of ultrasonic energy to correlate with performance of graphite fibre epoxy matrix composites exposed to thermal degradation, and also that analyses with the three techniques all pointed to the same critical temperature at which thermally induced damage increased sharply [58],... 

Polymer matrix composites (PMCs), or fiber-reinforced plastics (FRPs). provide a wide range of properties and behavior. Materials with discontinuous fibers are slightly stiffer than conventional unreinforced plastics, whereas the fully aligned continuous fiber systems can record exceptionally high specific properties (property divided by density), exeeeding those of competing materials such as steel and aluminum. There are a virtually infinite number of materials, and material formats that can be combined to form a composite material, as shown in Table 1. 

Hubert P, Femlund G, Poursartip A. Autoclave processing for composites. In Advani S, Hsiao K-T, editors. Manufacturing techniques for polymer matrix composites (PMCs). Cambridge (UK) Woodhead Publishing Limited 2012. 

Manufacturing techniques for polymer matrix composites (PMCs)... 

CMCs are significantly different from monolithic ceramics, or even from fairly well understood polymer matrix composites (PMCs). The combination of limited duetility of the eeramic matrices and the highly aggressive environments in which they are intended to operate present notable challenges to defining eonstituent requirements. 

Historically, the processing routes moved from the isothermal CVI process to more cost-effective techniques such as gradient-CVI and liquid polymer or liquid silicon infiltration. These routes are faster and lead to shorter manufacture cycles than isothermal CVI and, especially the two liquid phase processes LPI and LSI, use technologies already developed for polymer matrix composites (PMC). 

Composite materials can also be broadly classified based simply on the matrix material used. This is often done more for processing than for performance purposes. Thus there are polymer-matrix composites (PMCs), ceramic-matrix composites (CMCs), or metal-matrix composites (MMCs). The last type is an advanced composite uncommon in biomedical applications and is mostly used for high-temperature applications. 

Composites usually consist of a reinforcing material embedded in various matrices (binder). The elfective method to increase the strength and to improve the overall properties of composites is to incorporate dispersed phases into the matrix which can be an either polymer or engineering materials such as ceramics or metals. Hence, metal matrix composites (MMCs), ceramic matrix composites (CMCs) and polymer matrix composites (PMCs) are obtained. Besides, hybrid composites, metal/ceramic/polymer composites and carbon matrix composites can also be obtained. MMC and CMC composites are developed to withstand high temperature applications. MMCs are also used in heat dissipation/electronic transmission applications due to the conductive nature of metals (electrically and thermally). 

Polymer matrix composites (PMCs) are very popular due to their low cost, simple fabrication methods, lightweight and desirable mechanical properties. 

In composites, the matrix can be either polymeric, ceramic or metallic, hence, polymer matrix composites (PMC), ceramic matrix composites (CMC) or metal matrix composites (MMC). Obviously, the latter two structures are used for high temperature applications (>315 °C), where PMC are usually inadequate. In addition, MMC with proper electrical and thermal conductivities are also used in heat dissipation/electronic transmission applications. In addition to the general types of composites, some specific composites can also be of the type ceramic/metal/polymer or carbon matrix (CMC) or even hybrid composites (HC). 

---