Akademik Veri Yönetim Sistemi
TESTEG2023, Gaziantep, Türkiye, 13 - 15 Ekim 2023, ss.525-526
was discarded in 2022. Polyester is the most common fiberin textile industry with 54% fiber production rate. However, recycled polyester amount is only %15 of the global PET production. On the other hand, 99% of recycled polyester came from mechanically recycled PET bottles and only 1% came from chemically and biologically recycled polyester materials.
Mechanical recycling is a low-cost process but it reduced fiber quality and dyeability because of thermal degradation which is occurs due to melt processing and resulting in a drop of molecular weight and polymer component lost. So, these recycled materials can be only used for down cycle materials or blended with virgin polymers.
Therefore, chemical recycling is becoming a suitable alternative for obtaining sustainable upcycling or equal new products. Chemical recycling process includes dissolution or depolymerization of polymers, by using temperature, pressure, solvents, reagents, or a combination of them. Upcycled textiles can be produced by chemical recycling because, with this process all dyes, pigments chemical additives, fillers and functional coating can be eliminated and a new polymer can be produced, which have similar properties like virgin ones.
Depolymerization of waste polyester to its monomers can be achieved with several methods like hydrolysis, glycolysis, ammonolysis, aminolysis, methanolysis, hydrothermal liquefaction, pyrolysis and gasification. 75–95% monomer recovery can be obtained with depolymerization process and new polyester can be produce by polymerization of these monomers which have identical properties to virgin monomers.