From Reinforced Plastics to Composite Materials

The relation between microstructure and properties at the macro-scale is only one face of materials science. The second step consists in working on the relation between functions and properties. Structure/properties/functions are like the three summits of the base triangle of material science. [14] Contemporary materials are tailored for specific purposes, they are adapted to a set of specific tasks. In contrast to conventional materials that have standard specifications and a world market, more advanced materials are developed according to the functional demands of the final product and the services expected from the manufactured product. In other words, in the language of economics, instead of supplying commodities that would be finalized by the customers, new materials are the end-products of a cooperation between customers and suppliers. 

However, the technology of composite materials cannot be fully considered as a new chapter in the history of chemistry. Originally the term composite was used in conjunction with reinforced plastics. The US Society for Plastic Industries had a Reinforced Plastics Division which was renamed Reinforced Plastics and Composites Division, in 1967. [17] In France, a bi-monthly magazine entitled Plastique renforce/Verre textile published by the professional organization bearing the same name, started in 1963 and was rechristened in 1983 Composites with Plastique renforce/verre textile as a subtitle. The shift from reinforced plastics to composite 

A composite is a material whose assembly of constituent elements generates an effect of synergy within the properties of these elements. This bi- or tri- dimensional assembly is constituted by two or more basic elements, that can have all possible kinds of forms matrices, fibres, particles, plaques, sheets. .. It allows to obtain a resilient material, whose all elements are strongly and durably attached together. [19] 

A third interesting aspect of this story is that Du Pont s aramide fiber was not specifically the result of market-driven research. When this fiber was patented in 1971 there was no commercial application in view. However, within ten years, three varieties of Kevlar fiber were commercialized by Du Pont for dozens of reinforced plastic applications in radial passenger tires, belts, in protective clothing, such as gloves or ballistic and flak vests, in ropes and cables in racing kayaks and canoes, and in commercial aircraft. Thus the Kevlar fiber by no means resulted from the functional, bottom-up, approach which is sometimes considered as a major characteristic of materials science. The aramide fiber resulted from the traditional style of industrial research which was successful in the plastic era and confirms the leadership of chemistry in materials technologies. 

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