Polyethylene terephthalate (PET) resin is sold as virgin material for soft drink bottles and other consumer products. After their use, most PET bottles are discarded as waste. PET scrap is a good source of terephthalic acid (TPA), a fossil-based raw material used in the manufacture of many polyesters, such as polybutylene terephthalate (PBT). PBT is commonly used in durable applications such as automotive components, electrical devices, connectors, and circuit breakers.
SABIC Innovative Plastics has developed a novel approach to chemically upcycle PET waste into durable PBT-based products. The PET waste is chemically decomposed to its oligomers and the recovered TPA oligomers are used to manufacture Valox iQ* PBT neat resin. The ethylene glycol monomer is also recovered and used to prepare polyesters. The Valox iQ PBT neat resin made in this way, and the molding compositions containing Valox iQ neat resins, exhibit equivalent performance properties as conventionally-made materials. This chemical upcycling process converts a single use, non-durable PET application like water bottles into molding compositions containing Valox iQ PBT neat resins that are used in durable applications such as automotive and electronic parts. This new family of more environmentally sustainable products has been commercialized under the trade names "Valox iQ" and "Xenoy iQ*" resins. The environmental benefits of Valox iQ and Xenoy iQ resins include up to: 55-75% reduction of carbon dioxide emissions; 65% carbon content from recycled waste, and 55-75% reduction of process energy utilization per kilogram of PBT resin used.