Synthetic polymer, early

The calixarenes (from the Greek calix, meaning chalice) are a family of structures that have seen extensive use in many contexts. Shown below is the remarkable, one-step synthesis of the prototype calixarene. This condensation reaction is a variant of the phenol-aldehyde condensation that produces bakelite, the first synthetic polymer. Early workers spent considerable effort to optimize this synthesis, biasing the product toward the calixarene... 

It has been a long way from early synthetic polymers created as artificial substitutes (Kunststoffe) for scarcening metal resources, to modem materials tailormade to fill specific functions through particular properties and processing characteristics in many areas of application. Ever since they were first prepared, surprising new or improved properties have been discovered or engineered. 

Natural polymers are far more complex materials, being exclusively "organic", that is, products of life (cellulose, proteins, DNA,...). Nevertheless, as nature seems to have formed (size, weight, hardness, etc.) several natural polymers (wood, bones, ivory, etc.) in such a way as to be almost immediately usable by our ancestors, they were most probably the bases of the first human tools. The commonly widespread conception that polymers are the youngest "materials" in the historical world is not true, but, strictly speaking, only applies to synthetic polymers, which were discovered about 100 years ago, early in the XXth century. 

The word "polymer" (first proposed by Berzelius in 1833) is made of "poly" from the ancient Greek word "mlvq" meaning "many" and "pepot " meaning "part". Polymers are molecules built up from numerous identical chemical "units" spatially repeated to form a chain. From the early times and still nowadays, a distinction is often made between "natural" and "synthetic" polymers, but it is somewhat artificial as natural polymers can now sometimes be synthesized (e.g., synthetic "natural rubber") and some synthetic polymers, which are never found in nature, can be synthesized by natural ways (enzymatic syntheses). 

Some important everyday items that are made from polymers with widely different properties Include billiard balls, plastic dishes, soda bottles, barrier and decorative films, egg cartons, polymeric drinking glasses, foam seats, and automotive tires. These applications for synthetic polymers have developed over about 150 years. As shown in Table 2.1, modern polymer material science and technology can be traced back to as early as 1770 [1]. Some Important advances In the understanding of polymer production were developed before World War II. 

Nobel laureate Emil Fischer elucidated the c bohydrates and proteins, and Leo Baekeland prodi synthetic polymer in the early part of the 20th cen many other synthetic polymers developed in the firs were produced without much knowledge of po ym<... 

Surface Area. Given a particular affinity of the adsorbent surface for the dissolved solute, the effectiveness of the solid adsorbent for accumulation is directly proportional to the surface area. This theoretical conclusion is supported by experimental results from many laboratories, only a few of which are cited (143, 181, 207, 423). The value of surface area was realized first in the early investigations of activated carbons (1-4) and later in the initial studies of synthetic polymers (76, 78, 116). The first polymer investigations relied on the work of Kun and Kunin (539), who introduced the macroporous... 

Many of the applications in which polymers are used are based on the fact that they tend not to conduct an electrical current very well. For example, one reason for the enormous popular success of the first entirely synthetic polymer, Bakelite, in the early 1900s was its outstanding electrical insulation properties, just the characteristic needed for a host of applications in the new and growing held of electrical appliances. Within a decade after its discovery, Bakelite was being used for housing and casings for industrial and household electrical equipment and for insulation on electrical wires and structures. For the past century, the applications of many different kinds of polymers in electrical insulation have become legendary. 

Since the days of Staudinger [29] and the birth of polymer science early in this century, vast arrays of oligomers and high-molar-mass synthetic polymers have been produced with coil dimensions well over 10 A [30]. Although many advances... 

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