Polyester manufacture

Purified terephthahc acid became commercially available from Amoco Chemical Co. in 1965, by which time a considerable polyester industry based on dimethyl terephthalate had already developed. The Amoco process involves purification of cmde terephthahc acid by a separate step to attain the high product purity required for polyester manufacture. The Amoco technology is the most-used worldwide, but other processes have been developed and are operating commercially. 

With the exception of the soHd methoxide [19727-40-3], the lower antimony trialkoxides are colorless or slightly colored distillable Hquids, easily hydroly2ed. Thermally these alkoxides are rather stable. The lower antimony trialkoxides are manufactured from antimony trichloride, the higher from antimony trioxide, both on a small scale. They are used in polyester manufacture, in fireproofing, as catalysts, and for coatings. For further information about antimony trialkoxides, see references 21, 65, 98. 

Transesterification is a crucial step in several industrial processes such as (i) production of higher acrylates from methylmethacrylate (for applications in resins and paints), (ii) polyethene terephthalate (PET) production from dimethyl terephthalate (DMT) and ethene glycol (in polyester manufacturing),... 

Polyester manufacture, organic titanium compounds in, 25 123 Polyester materials, recycling, 20 22 Polyester/polyether/polycarbonate,... 

Terephthalic acid is commonly abbreviated TA or TPA. The abbreviation PTA (P = pure) is reserved for the product of 99% purity for polyester manufacture. For many years polyesters had to be made from dimethyl terephthalate (DMT) because the acid could not be made pure enough economically. Now either can be used. TA is made by air oxidation of /7-xylene in acetic acid as a solvent in the presence of cobalt, manganese, and bromide ions as catalysts at 200°C and 400 psi. TA of 99.6% purity is formed in 90% yield. This is called the Amoco process. 

MEG quality and performance of the MEG product in derivatives (polyesters) manufacturing have been demonstrated to be at least as good as and fully compatible with MEG produced via the thermal process. 

Figure 1-22. Flow diagram of polyester manufacturing process.

This route accounts for most polyester manufacture (for production and price data, see above Figures 6.27 and 6.28, respectively). However, the direct polyesterilication of ethylene glycol with terephthalic acid is becoming important ... 

MAJOR USES Intermediate for polychlorinated biphenyls organic synthesis heat transfer agent plant disease control dyeing assistant for polyesters manufacturing of benzidine fun-gistat in packaging of citrus fruit. 

It is obvious from Equation 6 that for a high value of X , the concentration of water in the reaction mixture must be minimized. Since K, K, the need to reduce the concentration of water in polyester manufacture is more important in the manufacture of nylon 6,6. Consequently, the final stages of polyester manufacture are carried out at reduced pressures. 

Textiles used as fabric fagades are commonly a coated mesh. This allows a view out and reduces energy consumption while providing solar protection (Armijos, 2008). The most common types are PVC-coated polyester manufactured into a coated or extruded product, PTFE (poly-tetrafluoroethylene or Teflon) coated flbreglass mesh, and ETFE (ethylene-tetrafluoroethylene) foils. 

Electrospun Scaffolds of Biodegradable Polyesters Manufacturing and Biomedical Application... 

Leguval Unsaturated polyester, manufactured by Bayer, Germany. 

Baxenden Chemicals Ltd. (UK) has developed a large scale lipase-catalyzed process for the production of poly (hexane-1,6-diol adipate). The process consists of condensation of hexane-1,6-diol and adipic acid using Candida antaictica lipase. Constant removal of water from the enzyme-catalyzed polymerization process is crucial to shift the equilibrium to the right. This simple lipase-catalyzed polyester manufacture is operated at ambient temperature and does not require a solvent. In addition, the process is very economical when compared to the chemical process. 

---