Plastics earliest

The earliest ball and stick models were exactly that wooden balls in which holes were drilled to ac commodate dowels that connected the atoms Plastic versions including relatively inexpensive student sets became available in the 1960s and proved to be a valuable learning aid Precisely scaled stainless steel framework and plastic space filling models although relatively expensive were standard equipment in most research laboratories... 

Whereas celluloid was the first plastics material obtained by chemical modification of a polymer to be exploited, the phenolics were the first commercially successful fully synthetic resins. It is interesting to note that in 1963, by a merger of two subsidiary companies of the Union Carbide and the Distillers organisations, there was formed the Bakelite Xylonite Company, an intriguing marriage of two of the earliest names in the plastics industry. 

Glass in the form of fibres is relatively inexpensive and is the principal form of reinforcement used in plastics. The fibres are produced by drawing off continuous strands of glass from an orifice in the base of an electrically heated platinum crucible which contains the molten glass. The earliest successful glass reinforcement had a calcium-alumina borosilicate composition developed... 

With nanosecond time resolution, sensitive, accurate detectors, studies of these release waves have proven to be particularly revealing. First-order descriptions of release properties were obtained with rudimentary instrumentation from the earliest studies [65A01] it has required the most sophisticated modern instrumentation to provide the necessary detail to obtain a clear picture of the events. Characteristically different profiles are encountered in the strong-shock, elastic, and elastic-plastic regimes. 

Many ideas for advancing electrical and electronic systems have been adopted since the early 1940s, which saw the start of high electronic frequency radar systems. The earliest major use of plastics for electrical insulation early in last century come with the advent of developments in electrical... 

The use of rubber as a floor covering (continuous sheets, tiles or mats) was one of its earliest applications but is now being challenged by a variety of plastics, mainly PVC. 

From the earliest times man depended upon nature for polymeric materials like wood as fuel, furs and fibres as clothing, grain and flesh as food. Many polymeric materials behave as plastics, i.e., in some stage of their fabrication they are soft and putty like and can be moulded into any desired shape and then set to retain that shape. 

Phthalates were first introduced in the 1920s and quickly replaced the volatile and odorous camphor. In the earliest 1930s, the commercial availability of PVC and the development of DEHP caused the boom of the plasticizer PVC industry. 

With all the different substances that exist, you may be surprised to learn that they are formed from a relatively small number of elements. For example, carbon is one of about 109 known elements. Yet carbon can combine with other elements (like hydrogen and oxygen) to form thousands of substances (like sugar, alcohol, and plastics). Although some elements have been known from the earliest times, most were discovered during the last 300 years. 

Kinetite (Kinetit or Kinenite-Swiss). One of the earliest gelatinous (plastic) expls which contd no NG. It was patented in 1884 by Petry and Fallenstein and was used extensively at the end of the last century in Ger and other European countries. It was prepd by gelatinizing Nitrobenzene or Nitrotoluene with Collodion Cotton, and impregnating this plastic mass with sulfur, K chlorate and other ingredients. Sulfur was later replaced by Sb penta-sulfide. Its compn was NB 16.0 to 21.0, Collodion Cotton 0.75 to 1.0, K chlorate 82.5 to 75.0, Sb2Ss and/or K nitrate 3.0 to 1.0%. The function of the Sb pentasulfide was to render the explosion more regular and more complete... 

Gelatine-Cheddite (Swiss). Plastic chlorate expls invented in 1911 by C. Rubins and then manufd by the Schweizerische Sprengstoff AG Chcddite and Dynamit. These expls are srable and do not harden in storage. The prepn and oompn of one of the earliest formulations is given by Stettbacher in Ref 1. 

Basic dyes of the azo class were among the earliest known synthetic dyes. They were used originally for dyeing cotton mordanted with tannin and potassium antimonyl tartrate and wool from neutral solution. They continue to have minor importance for dyeing leather, paper, plastics, and waxes, and as constituents of graphic arts colors. 

Mother Nature has provided humans with a mind-boggling array of natural products with nearly every conceivable set of physical properties and, therefore, an apparently endless variety of uses. And yet, human inventors have always tried to go Mom one better, producing synthetic products that are longer lasting, less expensive, more attractive, or preferable to "the real thing" in some other way. Such has been the case, for example, in the more than century-and-a-half development of plastics. One of the earliest pioneers in the evolution of the plastics industry was John Wesley Hyatt, an inventor who spent his whole life trying to devise new and better materials and improved methods for getting jobs done. 

And yet, during the decade when Mr. McGuire was offering his advice to Benjamin Braddock, the plastics industry in the United States was truly in its infancy. In 1930, one of the earliest years of the polymer industry s existence, only 15,000 tons of the material... 

The deposition under vacuum of a thin metallic film is not a new technique and its application to plastics dates back now some years (the author s own earliest involvement was in the early fifties, with a view to the replacement of silver electroplating with aluminium reflective surfaces in motor vehicle headlamps). 

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.)... 

To meet specific needs, other additives such as lubricants, extenders, fillers, impact modifiers, and pigments are added to the PVC compound, in addition to heat stabilizers and plasticizers. Today, it is estimated that more than 60% of all the adducts used in plastics are used in PVC compounds. Although the earliest PVC compounds were produced as emulsions, essentially all PVC compounds are produced today as suspensions. Suspension compounds contain essentially no emulsifiers and are more processable. Liquid plastisols typically have room-temperature viscosities of less than 10,000 cp. Products made from plastisols are usually very soft. They have Shore Durometers of 55A and less, to as low as 30A, and they can have characteristic skin- or leather-like appearance and feel. 

The followers of a phase transformation toughening (PTT) state that the change from a less densely packed crystalline structure (f)) to a more packed one (a) (i) promotes microvoiding in the earliest stages of the deformation and (ii) facilitates plasticity due to its exothermic character [72,78,193]. 

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