Polymer earliest synthetic

The earliest synthetic resin to be used in commerce seems to have been a polyester then termed ester gum, which was made by esterifying rosin (essentially an unsaturated monocarboxylic terpenoid acid, abietic acid) with glycerol. When cooked with tung oil (a glycerol ester of 9,11,13-octadecatrienoic acid), this provided varnishes that dried overnight. In this case, the polymer is formed by an addition copolymerisation process, but the product is nevertheless also a polyester. 

Chloroprene rubber (Neoprene—trade name of DuPont) was one of the earliest synthetic rubbers, first commercialized in 1932. It has a wide range of useful properties but has not become a true general purpose synthetic rubber, probably because of its cost. It does possess properties superior to those of a number of general purpose polymers, such as oil, ozone, and heat resistance but for these properties other specialized polymers excel. Polychloroprene thus is positioned between the general purpose elastomers and the specialty rubbers. 

The earliest synthetic polymers were synthetic rubbers. Before 1920 natural rubber was the only available elastomer, but constant attempts, with varying degrees of success, to develop commercial rubber substitutes had been made previously, especially by Engfish and German chemists, who competed with each other in the search. 

The earliest synthetic bioresorbable polymers were based on linear aliphatic polyesters. More recently, many other classes of polymers have been explored to develop new resorbable systems for various biomedical applications. Today, a variety of polymer systems having tailored bioresorption profiles are being used or researched for specific biomedical applications. All these bioresorbable polymeric... 

Poly(vinyl dnnamate) is the earliest synthetic photo-polymer Its molecular structure, the polyvinyl backbone with dnnamoyl side drains, was proposed with the expectation that the photocycloaddition of polymer-bound dnnamoyl groups would crosslink adjacent macromolecules. The practical aims of the inventors were realized, and the whole range of successful photopolymos has been developed from the ordinal idea However, the actual mechanism of oosslink formation in these systems remained unclarified untD recently. Repeated attonpts to identify cyclobutane derivatives in irradiated films of poly(vinyl dimamate) failed with traces of a-truxiUic acid detected in the hydrolyzed material only at the very early stage of irradiation. Schmidt... 

The earliest synthetic materials applied as lining adhesives were either solvent cast or emulsified copolymers or homopolymers of vinylacetate or methacrylate polymers. These materials are admired because they do not respond to changes in relative humidity because of their reduced amount of functional groups capable of forming hydrogen bonds with moisture present in air. 

Polysulfides. The polysulftde elastomer, best known under the trade name Thiokol, represents the earliest commercially developed synthetic mbber, developed ia 1930 by J. C. Patrick as a highly solvent and age-resistant elastomer (15). It is stiH considered the most solvent-resistant mbber, but its poor mechanical properties provide a serious disadvantage (see Polymers containing sulfur). 

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. 

Literature articles, which report the formation and evaluation of difunctional cyanoacrylate monomers, have been published. The preparation of the difunctional monomers required an alternative synthetic method than the standard Knoevenagel reaction for the monofunctional monomers, because the crosslinked polymer thermally decomposes before it can revert back to the free monomer. The earliest report for the preparation of a difunctional cyanoacrylate monomer involved a reverse Diels-Alder reaction of a dicyanoacrylate precursor [16,17]. Later reports described a transesterification with a dicyanoacrylic acid [18] or their formation from the oxidation of a diphenylselenide precursor, seen in Eq. 3 for the dicyanoacrylate ester of butanediol, 7 [6]. 

In another line of research, scientists began to look for synthetic materials from which artificial blood vessels could he manufactured. Some of the earliest materials to be tried were synthetic fibers, such as nylon, vinyon (a polymer consisting primarily of vinyl chloride), and ivalon (a polymer of vinyl alcohol). These materials were largely unsuccessful because they tended to lose their strength too quickly after implantation. 

Stationary Phases. The stationary phases used in SEC are solids ranging from synthetic polymers to glasses. The earliest ones were soft gels, which cannot be used at high pressures. Consequently, the development of new phases has paralleled somewhat the development of more rigid resins and gels in IEC, as noted earlier. Some phases and their trade names are given in Table 12. 

Continuous emulsion polymerization processes are industrially important for the large-scale production of synthetic polymer latexes, and have been used particularly where the solid polymer is to be recovered by coagulating the polymer latex. St-Bu rubber latex was one of the earliest latex products manufactured using continuous emulsion polymerization processes consisting of a number of stirred-tank reactors in series (CSTRs). Since the 1940s, continuous emulsion polymerization processes have been developed for a variety of products and with different reactor configurations [328]. This is because these continuous reactor systems have several advantages, such as [329] ... 

The earliest polymers of practical use were prepared by step-growth reactions, most notable among them Bakelite, a phenol-formaldehyde copolymer first marketed in 1910 [4]. Its name was long almost synonymous with synthetic plastics and resins, has become generic, and is no longer restricted to phenol-formaldehyde copolymers. Most but not all step-growth polymerizations are condensations. 

From the outset polymer science has involved physicists, chemists, engineers, materials scientists and design engineers. The multidisciplinary nature of polymer science from its earliest days is a feature that is not often exhibited by other fields of natural science until a certain maturity has been reached. The synthetic polymer industry in the UK expanded greatly over the years from... 

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. 

Gel chromatography was originally used for separation of biological materials, because the earliest gel media, cross-linked dextrans, were suitable for use only with an aqueous system. In 1964 [26], cross-linked polystyrene gels suitable for use with organic solvents were first produced, and this made possible the extension of gel chromatography to the separation and characterisation of synthetic polymers. Application of the method, not only to a... 

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