Early Polymer Industry

The history of synthetic polymers is incredibly short. The term polymer was introduced in 1832. The first synthetic polymer (phenol-formaldehyde) was commercialized as Bakelite in 1909, while the first thermoplastic (polystyrene, Trolitul ), 6 years later. The early polymer industry was developed by entrepreneurs that had little if any technical background. The commercial successes (and... 

In an extension of an early work on the nickel-catalyzed addition of hydrogen cyanide to unsaturated compounds, a basic reaction in various large-scale processes in the polymer industry, the hydrocyanation of butadiene (equation 15) and the efficiency of catalysis of this reaction by low-cost copper salts has been studied extensively by Belgium researchers47,48. 

Historically, the reaction of phenol with formaldehyde was of vital importance to the polymer industry, being one of the first totally synthetic commercial polymer resin systems developed. In 1907, Leo H. Baekeland commercialized, under the tradename Bakelite , a range of cured phenol-formaldehyde resins, which were useful in producing heat-resistant molded products . Since this early work, phenol-formaldehyde resins have been used in many applications, including refractory compounds, adhesives, thermal insulation and electrical industries ". ... 

The polymer industry traces its beginning to the early modifications of shellac, natural rubber (NR — an amorphous c -l,4-polyisoprene), gutta-percha (GP — a semi-crystalline trfl i-l,4-polyisoprene), and cellulose. In 1846, Parkes patented the first polymer blend NR with GP partially co-dissolved in CSj. Blending these two isomers resulted in partially crosslinked (co-vulcanized) materials whose rigidity was controllable by composition. The blends had many apphcations ranging from picture frames, table-ware, ear-trumpets, to sheathing the first submarine cables. 

The history of implementing new materials systems is littered with the remains of unanticipated failure modes encountered in service. For example, environmental effects and a general lack of understanding of the failures in earhon/ epoxy fan blades devastated the early PMC industry in the 1960s. The effects of rain and sand caused significant erosion of the polymer matrices, and the inability of PMCs to survive... 

In the early 1960s, UHMWPE was classified as a form of HDPE among members of the polymer industry (Chubberley 1965). Thus, Chamley s earlier references fo UHMWPE as HDPE are fechnically accurafe for his time (Chamley 1963), but they have contributed to some confusion over the years as to exactly what kinds of polyethylenes have been used clinically. From a close reading of Chamley s works, it is clear that HDPE is used synonymously with RCH-1000, the trade name for UHMWPE produced by Hoechst in Germany (Chamley 1979). With the exception of a small series of 22 patients who were implanted with silane-crosslinked HDPE at Wrighington (Wroblewski et al. 1996), there is no evidence in the literature that lower molecular weight polyethylenes have been used clinically. 

It is useful at this point to consider the definition of an additive as given by the EC (European Commission) an additive is a substance, which is incorporated into plastics to achieve a technical effect in the finished product, and is intended to be an essential part of the finished product. Since the very early stages of the development of the polymer industry, it was realized that useful materials could only be obtained if certain additives were incorporated into the polymer matrix, in a process normally known as compounding. Additives confer on plastics significant extensions of properties in one or more directions, such as general durability, stiffness and strength, impact resistance, thermal resistance, resistance to flexure and wear, acoustic isolation, etc [86]. 

The above mentioned processes are in use with much success in the polymer industry for a long time. A few other methods are reported by researchers, which has been successful in certain systems. These include solid intercalation, co-vulcanization and the sol-gel method. Some of these methods are in the early stages of development and have not yet been widely applied. 

Putrescine (diaminobutane, DAB) is a widely abundant biogenic diamine [7]. It found early apphcation in the polymer industry as a building block for the synthesis of PA4.6, though not of biological origin [25]. Indeed, current production relies on propylene from petrochemistry, ammonium, and hydrocyanic acid [25]. The common occurrence in bacteria [7], however, promised a reasonable basis for bio-based production, thus stimulating research on fermentation processes. 

The basic thrust of the polymer industry began changing in the early 1900s, when chemists began to make commercial scale synthetic polymers. Although the first synthetic polymers were made in the late 1830s, they... 

The appearance of the polymer industry as an important segment of this country s economy occurred shortly after W.W. II. Prior to this time, production was limited by shortages caused by the war effort as well as the newness of the materials themselves. About the only polymers available for production in the early 1950 s were nylons, polyethylene, polystyrene, phenolics, cellulosics, PVC, acrylics, silicones, ABS, polyesters, and rubbers. Today there are approximately UO major classes of polymeric materials produced in commercial quantities as well as some rather exotic materials developed for specific uses. During this 25 year period, new polymers, new methods of producing already important polymers as well as new ways of utilizing these materials, were being developed. 

Composite materials have been known for many thousands of years. Among the earliest uses were the boat-building materials prominent in the Middle East about 5000 bc composed of reeds with a pitch binder and the laminated wood composites crafted in Thebes around 1500 BC. From the early days of the polymer industry, it was appreciated that the final properties of polymers could be significantly enhanced by the use of inorganic fillers to form a composite. Today fillers are routinely used to tailor properties such as thermal expansion, conductivity, flammability and mechanical performance, and even to reduce cost. 

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