Whinfield

However, because of the low melting poiats and poor hydrolytic stabiUty of polyesters from available iatermediates, Carothers shifted his attention to linear ahphatic polyamides and created nylon as the first commercial synthetic fiber. It was nearly 10 years before. R. Whinfield and J. T. Dickson were to discover the merits of poly(ethylene terephthalate) [25038-59-9] (PET) made from aromatic terephthaUc acid [100-21-0] (TA) and ethylene glycol [107-21-1] (2G). 

Carothers also produced a number of aliphatic linear polyesters but these did not fulfil his requirements for a fibre-forming polymer which were eventually met by the polyamide, nylon 66. As a consequence the polyesters were discarded by Carothers. However, in 1941 Whinfield and Dickson working at the Calico Printers Association in England announced the discovery of a fibre from poly(ethylene terephthalate). Prompted by the success of such a polymer, Farbenfabriken Bayer initiated a programme in search of other useful polymers containing aromatic rings in the main chain. Carbonic acid derivatives were reacted with many dihydroxy compounds and one of these, bis-phenol A, produced a polymer of immediate promise. 

Linear polyesters were studied by Carothers during his classieal researches into the development of the nylons but it was left to Whinfield and Dickson to discover polyfethylene terephthalate) (BP 578079), now of great importance in the manufacture of fibres (e.g. Terylene, Dacron) and films (e.g. Melinex, Mylar). The fibres were first announced in 1941. 

Polyesters are the most important class of synthetic fibers. In general, polyesters are produced by an esterification reaction of a diol and a diacid. Carothers (1930) was the first to try to synthesize a polyester fiber by reacting an aliphatic diacid with a diol. The polymers were not suitable because of their low melting points. However, he was successful in preparing the first synthetic fiber (nylon 66). In 1946, Whinfield and Dickson prepared the first polyester polymer by using terephthalic acid (an aromatic diacid) and ethylene glycol. 

In UK, in 1941, Whinfield and Dickson discovered the polyester fibre called terylene chemically it is polyethylene terephthalate. Teryene polymer can be melt spun into a fibre which is widely used in textile industry. 

Figure 1.3 J. R. Whinfield (left) and J. T. Dickson (right) re-enact the discovery of fibre-forming poly(ethylene terephthalate) [30] (photograph circa 1942)...

In 1953, E. F. Izard of du Pont was awarded the Schoellkopf Medal of the American Chemical Society. The report [36] of this award states that work on the development of a hydrolytically stable polyester was started by Dr Izard in 1944, and it led in a comparatively short time to the discovery of polyethylene terephthalate . The report recognises that polyethylene terephthalate was earlier discovered independently in England by J. R. Whinfield . Izard himself says [37] that the duPont research programme led immediately to the discovery of poly(ethylene terephthalate) (PET), which suggests that detailed information from ICI about the structure of the new fibre had not yet reached him by that time. 

Other US companies chose to await expiration of the Whinfield and Dickson patent before entering the market. One of the earliest to become involved was Celanese Corporation, whose joint venture with ICI, named Fiber Industries Inc. (FII Fortrel), began construction of its first PET plant in 1959. Beaunit (Vycron) was also an early entrant, initially with a copolymer fibre that was arguably not covered by the basic patent, using polymer from Goodyear. 

Polyester has become a mainstay commodity material. This is one material that everyone comes in contact with daily for example, it is used in clothing, bedding, upholstery and carpeting. The first patent to cover polyesters was filed in 1941 by Whinfield and Dickson, with the material defined as a polymer formed by the combination of a diacid and a diol [1]. Following this discovery, the first commercial polyester, polyethylene 1,4-terephthalate) (PET), was produced by condensation polymerization of terephthalic acid (TA) (or dimethyl terephthalate (DMT)) as the diacid moiety and ethylene glycol as the diol. PET is now a well-known and widely utilized polymer material that is used throughout the world to manufacture films and fibers. 

Poly(trimethylene terephthalate) (PTT) is a newly commercialized aromatic polyester. Although available in commercial quantities only as recently as 1998 [1], it was one of the three high-melting-point aromatic polyesters first synthesized by Whinfield and Dickson [2] nearly 60 years ago. Two of these polyesters, polyethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT), have become well-established high-volume polymers. PTT has remained an obscure polymer until recent times because one of its monomers, 1,3-propanediol (PDO), was not readily available. PDO was sold as a small-volume fine chemical at more than 10/lb., and was therefore not suitable as a raw material for commercial polymers. 

Developed by Whinfield and Dixon in the U.K. Originally made by transesterification of DMT and ethylene glycol in a 1 2.4 ratio, distillation of the methanol, then polymerization at 200-290°C in vacuo with SbOs as catalyst. 

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