Bakelite, development

One of the first man-made polymers was Parkesine, so named after its inventor Alexander Parkes. It was introduced in about 1862 but was not a commercial success (Fried, (1995)). However, this early effort led to the development of celluloid (cellulose nitrate) by John Hyatt in 1870 which was a commercial success. The first truly synthetic polymer was a phenol-formaldehyde resin called Bakelite developed in 1907 by Leo Baekeland but it would be two more decades before the nature of the polymerization process would be understood sufficiently to develop polymers based upon a rational process. 

Baekeland in America obtained his first patent for materials prepared from these two compounds. In 1910 he founded the General Bakelite Company to exploit this development, in the process making phenol-formaldehydes, the first synthetic polymers to achieve commercial importance. 

Baekeland had to make important discoveries before he could bridge the gap between the initial concept and final products. In particular, he found that the base-catalysed condensation of phenol and formaldehyde can be carried out in two parts. If the process is carefully controlled, an intermediate product can be isolated, either as a liquid or a solid, depending on the extent of reaction. At this stage, the material consists of essentially linear molecules and is both fusible and soluble in appropriate solvents. When heated under pressure to 150 °C, this intermediate is converted to the hard, infusible solid known as bakelite . This second stage is the one at which the three-dimensional cross-linked network develops. 

Percy Reboul. Britain and the Bakelite Revolution. In The Development of Plastics. S. T. I. Mossman and P. J. T. Morris, eds. The Development of Plastics. London Royal Society of Chemistry (1994) 26-37. Source for early plastics. 

Baekeland A process for making organic polymers by reacting phenols with formaldehyde. Based on an observation by A. von Bayer in 1872 and developed into an industrial process by L. H. Baekeland from 1905 to 1909. It was used to make Bakelite, one of the first commercial plastics. The first industrial manufacture began in Germany in 1910. 

One product that has been developed for mercury cells is a loose liner (Fig. 23.14), which is fitted on-site in the anode workshop and fastened with titanium nuts (Fig. 23.15). The riser tube is tightened using a Bakelite pressure plate. 

Frederick Frey and Walter Shultze were instrumental early researchers. Frey was among the first to dehydrogenate paraffins catalytically to olefins and then the olefins to diolefins that serve as feedstocks to the production of many of today s polymers. In competition with Bakelite, he discovered the preparation of polysulfone polymers made from the reaction of sulfur dioxide and olefins creating a hard Bakelite-like material. Frey and Schultz also developed a process that allowed the production of 1,3-butadiene from butane that allowed the synthesis of SR. 

Trade (and/or brand) names and abbreviations are often used to describe a particular material or a group of materials. They may be used to identify the product of a manufacturer, processor, or fabricator, and may be associated with a particular product or with a material or modified material, or a material grouping. Trade names are used to describe specific groups of materials that are produced by a specific company or under license of that company. Bakelite is the trade name given for the phenol-formaldehyde condensation developed by Baekeland. A sweater whose material is described as containing Orion contains polyacrylonitrile fibers that are protected under the Orion trademark and produced or licensed to be produced by the holder of the Orion trademark. Carina, Cobex, Dacovin,... 

Since the development of Bakelite, many other types of plastic have appeared. Plastics have a huge number of applications today, including bags and containers of all shapes and varieties. 

Phenol—formaldehyde (PF) was the first of the synthetic adhesives developed. By combining phenol with formaldehyde, which has exceptional cross-linking abilities with many chemicals and materials, and a small amount of sodium hydroxide, a resin was obtained. The first resins solidified as they cooled, and it was discovered that if it was ground to a powder with a small amount of additional formaldehyde and the application of more heat, the mixture would liquify and then convert to a permanently hard material. Upon combination of the powdered resin mixture with a filler material such as wood flour, the result then being placed in a mold and pressed under heat and pressure, a hard, durable, black plastic material was found to result. For many years these resulting products were called Bakelite, the trade name of the inventor. Bakelite products are still produced today, but this use accounts for only a small portion of the PF resins used. 

One of the earliest commercial plastics was Bakelite , formed by the reaction of phenol with a little more than one equivalent of formaldehyde under acidic or basic conditions. Baeyer first discovered this reaction in 1872, and practical methods for casting and molding Bakelite were developed around 1909. Phenol-formaldehyde plastics and resins (also called phenolics) are highly cross-linked because each phenol ring has three sites (two ortho and one para) that can be linked by condensation with formaldehyde. Suggest a general structure for a phenol-formaldehyde resin, and propose a mechanism for its formation under acidic conditions. (Hint Condensation of phenol with formaldehyde resembles the condensation of phenol with acetone, used in Problem 26-17, to make bisphenol A.)... 

Synthetic polymer materials are so ubiquitous in modem life that we now take them for granted. But, the first commercially significant, completely synthetic plastic was only introduced at the beginning of the 20th century. This was Bakelite, invented by Leo Baekeland and a short account of his contributions will form the subject of one of our Polymer Milestones in the next chapter. The introduction of this new material was preceded by roughly 40 years of the development of what can be called semi-synthetics based on chemically modified forms of cellulose. 

But that is a story that we will tell later. Here % we will consider the events that led to the t development of the first true synthetic plastic, Bakelite, and the recognition of the existence of very large molecules or polymers. 

Celluloid was one of the early plastics that was used in numerous ways. It was made of cellulose nitrate and was extremely combustible, but a safer version, cellulose acetate, was later developed. Dyed black, they are reasonable imitations of jet but th have a plasticy look and feel. Black celluloid gives a fldnt, black streak. Baikelite, or phenol formaldehyde, could be dyed any colour and was widely used. When dyed black, it was also a reasonable jet imitation, but it dulls with age and has a plasticl look and feel. Black Bakelite gives a black streak. 

In 1909 the first true plastic was developed by reacting phenolic-formaldehyde (Bakelite) in the presence of a (propriety) catalyst. It was done by L. Hendrik Baekeland [3] who coined the word plastic , a substance he created from coal tar. The material had excellent heat resistance and low electrical conductivity and when blended with mica, clays, asbestos, etc., had considerable strength and resistance. In recent years, these materials have been used as part of manufacture to make casings for clocks, toasters and radios, among other things. 

The first plastic was a mixture of cellulose nitrate and camphor invented in the 1860s by John Wesley Hyatt it was given the TM Celluloid. In 1899 Spit-teler developed a method of hardening casein with formaldehyde and thus founded the casein plastics industry, e.g., small items such as buttons. The earliest high-volume plastic, a condensation product of phenol and formaldehyde, was introduced by Leo Baekeland in 1907. Trademarked Bakelite, it was the first truly synthetic high polymer. Its chief use was as engineering material since its dark color limited its application to items in which color was not a factor. 

We learned much from nature with these early attempts to produce useful polymer products based on modified, or reconstituted ( semisynthetic ) natural polymers, and many of these processes are still in use today. The first of the purely synthetic commercial polymers came with the small-scale introduction of Bakelite in 1907. This phenol-formaldehyde resin product was developed by Leon Baekeland. It rapidly became a commercial reality with the formation of The General Bakelite Company by Baekeland, and construction of a larger plant at Perth Amboy, New Jersey, in 1910. At about this time styrene was being combined with dienes in the early commercialization of processes to produce synthetic rubber. Polystyrene itself was not a commercial product in Germany until 1930 and in the U.S.A. in 1937. The only other purely synthetic polymers that made a commercial appearance during this early development period were polyvinyl chloride and polyvinyl acetate, both in the early 1920s. 

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 extended rod structures and flexible phenol/formaldehyde oligomers offer interesting opportunities in the development of nonlinear optical (NLO) materials and Bakelite modifiers, respectively. 

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