Polyesters first production

Glycols and epoxides react with maleic anhydride to give linear unsaturated polyesters (61,62). Ethylene glycol and maleic anhydride combine to form the following repeating unit. This reaction is the first step in industrially important polyester resin production (see Polyesters, unsaturated). 

PET is by far the largest-volume thermoplastic polyester in production today. It was first synthesized by J. R. Winfield in the UK in the 1940s and its first commercial application was as a textile fiber. PET was also produced as a film for packaging and blow molded into bottles for beverages long before it had any... 

Polyesters have played a prominent part in the development of biodegradable polymers. One of the first products developed as a biodegradable plastic in the early 1970s was based on a polyester belonging to the polyhydroxyalknoates (PHA) group, called polyhydroxybutyrate (PHB). 

Glyptal is also a polyester condensation product, but glycerol (HOCH2CHOHCH2OH) produces a cross-linked thermosetting resin. In the first stage a linear polymer is formed with the more reactive primary OH groups. 

The recovery and use of plastic bottles into RPET yams has had strong uptake from a number of apparel companies. Currently, OLR of PET bottles to fibre has had the greatest success for reuse as a material in the fashion sector, with an open loop of waste from the first product (PET bottles) used as feedstock for the second product system (polyester fabric to garment). A common approach is to blend the recycled yams with virgin fibres to create textiles that are of apparel quality. 

The first production of poly(3HB-co-3HV), P(3HB-co-3HV), from ohve oils by Aeromonas caviae was described by Doi et al. (1995). Here, the polyester content in the cells was stiU rather low (6-12%). The feasibihty of using olive oil mill effluents as a substrate in biodegradable polymer production was studied by Dionisi et al. (2005), where ohve oil mill effluents were anaerobicaUy fermented at various concentrations combined with different pretreatments and without pretreatment to obtain volatile fatty acids (VFAs) such as acetate, propionate, butyrate, isobutyrate and valerate, which were used as substrates for PHA production. Olive oil miU effluents were also tested for PHA production by using a mixed culture from an aerobic sequencing batch reactor where olive oil miU effluents were centrifuged and tested with or without fermentation. The best results with regard to PHA production were obtained with... 

Polyurethanes were first discovered by Otto Bayer and coworkers at I. G. Farbenindustrie, Germany, in the late 1930s. The first products were obtained by reacting an aliphatic diisocyanate with an aliphatic diamine or diol. These materials soon found commercial uses and were marketed under the trade names of Irgamid U, for plastics, and Perlon U for synthetic fibers and bristles. Very soon after this, it was discovered that isocyanates could be used to bond rubber to metal, which in turn led to the development of urethane adhesives based on polyester diols these adhesives were commercialized under the trade name Polystal. For a more complete account of the history of polyurethanes, see refs. 2, 4, and 5. 

The first products of bluesign s venture, made fi om synthetic fibers, have recently been introduced to the marketplace. Switzerland-based Schoeller Textil, a company known for its innovative performance fabrics, has produced a line of polyester fabrics made entirely without the use of environmental toxins. This new production process lowers energy consiunption by 85 percent and water consumption by 75 percent. The new production process for these fabrics requires less raw materials and eliminates toxic by-products, said Tom Weinbender, president, Schoeller Textil USA, Seattle, Wash. The quality of these cutting-edge fabrics is not compromised in any way, resulting in the same high standards that Schoeller customers expect. 

The polymerization of tetrahydrofuran was first studied ia the late 1930s (3,4). In 1960, this work was summarized (4), and the Hterature on tetrahydrofuran polymers and polymerization has been growing ever siace. Polytetrahydrofuran with hydroxy end groups has become a large-scale commercial product, used mainly as the flexible polyether segment ia elastomeric polyurethanes and polyesters. It is commercially available under the trade names Terathane (Du Pont), Polymeg (QO Chemicals), and PolyTHF (BASF). Comprehensive review articles and monographs have been pubUshed (2,5-8). 

The ketene—crotonaldehyde route through polyester with various modifications and improvements is reportedly practiced by Hoechst Celanese, Cheminova, Daicel, Ueno, Chisso, Nippon Gohsei, and Eastman Chemical Company. Differences in thein processes consist mosdy in the methods of polyester splitting and first-stage purification. Production of the potassium salt can be from finished sorbic acid or from a stream in the sorbic acid production route before the final drying step. Several patents on the process for producing sorbic acid and potassium sorbate from this route are given in the hterature. 

In 1923, the first disperse dye was developed for dyeing cellulose acetate fibers. However, in recent years the most important appHcation of disperse dyes has been to dye polyester fibers. Accompanied by the rapid growth of polyester fibers after World War II, disperse dyes have currendy achieved the largest production among all dye classes in terms of quantity (106). 

Cobalt naphthenate is generally supplied in solution in styrene, the solution commonly having a cobalt concentration of 0.5-1.0%. The cobalt solution is normally used in quantities of 0.5-4.0% based on the polyester. The accelerator solution is rather unstable as the styrene will tend to polymerise and thus although the accelerator may be metered from burettes, the latter will block up unless frequently cleaned. Cobalt naphthenate solutions in white spirit and dimethyl phthalate have proved unsatisfactory. In the first case dispersion is difficult and laminates remain highly coloured whilst with the latter inferior end-products are obtained and the solution is unstable. Stable solutions of cobalt octoate in dimethyl phthalate are possible and these are often preferred because they impart less colour to the laminate. 

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