Recycling, polyester

Eastman Chemical Company, MBC-231, Optisys Polyester Recycling Technology, Eastman Chemical Company, Kingsport, TN, 1999. 

Mueller RJ (2006) Biological degradation of synthetic polyesters - enzymes as potential catalysts for polyester recycling. Process Biochem 41 2124-2128... 

Textiles Environment Design. Polyester Recycling. Available at http //www.tedresearch.net/ media/files/Polyester Recycling.pdf. 

Recycled poly(ethylene terephthalate) (PET), which offers excellent properties at potentially lower cost, is finding wider use as a raw material component and meeting increasing demands for environmentally compatible resins (see POLYESTERS,THERMOPLASTIC Recycling, PLASTICS). 

Over 250,000 metric tons of microcrystaUine cellulose have been sold siace its commercialisation ia 1962 and demand continues to iacrease. Its utihty has led to development of other coUoidal polymer microcrystals (see Colloids). For example, polyamides and polyesters from recycled materials can be biodegraded to give microcrystals having a size of 30 nm (37). 

Acetic acid is then recovered and recycled. Butanediol is mainly used for the production of thermoplastic polyesters. 

Polyesters are now one of the economically most important classes of polymers, with an overall world production between 25 and 30 million tons in 2000, consisting mostly of PET. This production is rapidly increasing and is expected to continue to do so during the next decade, driven by packaging applications, due to a very favorable image of environmentally friendly and recyclable polymers in western countries, and by textile applications, due to a strong demand in the far-east area to satisfy the needs of an increasing population. 

Hie ester linkage of aliphatic and aliphatic-aromatic copolyesters can easily be cleaved by hydrolysis under alkaline, acid, or enzymatic catalysis. This feature makes polyesters very attractive for two related, but quite different, applications (i) bioresorbable, bioabsorbable, or bioerodible polymers and (ii) environmentally degradable and recyclable polymers. 

The primary UPR end markets are construction, automotive, and marine industries widi applications such as house paneling, tub and shower applications, chemical-resistant storage tanks, pultruded profiles, and fiberglass composite boat hulls. The UPR industry is mature, with a world production close to 1.7 million tons (Table 2.2), but must face two important issues increasingly strict regulations for styrene emissions and poor recycling potential for polyester thermosets.48 49... 

The major PET manufacturers are depolymerizing scrap PET with glycols (glycolysis) or methanol (methanolysis) to form low-molecular-weight polyester diols (and BHET) and dimethyl terephthalate.3 The purified products are then used to make new products. Goodyear uses glycolysis to make REPETE, a new product which contains 10-20% recycled PET. Hoechst Celanese used methanolysis to produce DMT for repolymerization. Eastman Chemicals uses depolymerization of PET to recover used X-ray scrap. 

Cements, polyester, 30 CFCs. See Chlorofluorocarbons (CFCs) Chain conformation, 54 Chain extenders, 213-214 structure of, 219 Chain extension, 216 Chain-growth polymerizations, 4 Char formation, 421, 423 Chelated phosphine ligands, 488 Chemical recycling, 208 Chemical structure... 

Mechanical properties. See also Dynamic mechanical analysis (DMA) of polyamides, 138 of polyester LCPs, 52 of polyurethanes, 242-244 of semicrystalline aromatic-aliphatic polyesters, 45 Mechanical recycling, 208 Medical applications, for polyurethanes, 207... 

The Vinyloop process was developed by Solvay as a response to a challenge from one of its customers, Ferrari Textiles Techniques (France), who produces architectural tarpaulin and canvas in PVC/polyester compound. This is a rather difficult formulation for recycling, since the PVC is mixed with a matrix. At the same time, Ferrari felt it was important that their material would be recyclable. The first Vinyloop installation is now operational. It is a form of mechanical rather than feedstock or chemical recycling, since the PVC matrix is not changed in the process. 

A pyrolysis technique was investigated as a method for the chemical recycling of glass fibre-reinforced unsaturated polyester SMC composites. The proeess yielded liquid products and gases and also a solid residue formed in the pyrolysis of glass fibres and fillers. The solid residue was used as a reinforeement/filler in unsaturated polyester BMC composites, and the influenee on mechanical properties was studied in comparison with BMC prepared entirely from virgin materials. 

Dallas, Texas, 6th-10th May, 2001, paper 389 POLYESTER POLYOLS FOR POLYURETHANES FROM RECYCLED PET... 

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