Introduction, Definitions and Classifications

Structural materials can be classified as metals, ceramics or polymers, each with its own advantages and disadvantages. For example, metals are strong, tough, inexpensive, but are heavy, chemically reactive and limited to service temperatures below 1,000 °C. Ceramics are hard, chemically stable and useful at high temperatures, but they are brittle and difficult to fabricate. Polymers are light, easy to process, but are relatively 

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). 

In this chapter, only PMC that are used in construction will be covered in any detail. 

In general, the following principle is used in the incorporation of dispersed phase into the matrix, in the production of a composite the matrices selected for use are of lower modulus, while the dispersed reinforcing elements are typically some 50 times stronger and 20-150 times stiffen One should note, that the properties of the matrix are particularly important in most polymer composite systems - as in such systems, the matrix bears the load and it is distributed between the matrix and reinforcing particles. Each matrix type with different incorporated phases certainly has a different impact on the processing technique to be used. 

By embedding natural and near-natural reinforcing fibres (such as flax, cellulose) into a biopolymeric matrix (from cellulose, starch or lactic acid derivatives, thermoplastics as well as thermosets), a new group of fibre reinforced systems are also created, called as biocomposites [28]. 

---

Wilkinson DS (1994) Introduction, definition and classification. In Menne T, Maibach H (eds) Hand eczema. CRC Press, Boca Raton, pp 1-12... 

---