Chemical Recycling of PET in the Presence of the Bio-Based Polymers, PLA, PHB and PEF: A Review

The great increase in the production and consumption of plastics has resulted large amounts plastic wastes, creating a serious problem terms their environmentally friendly disposal. need for more polymers gave birth to biodegradable, recently, biobased polymers, used biodegradable or plastics. Although percentage currently produced bioplastics is rather small, almost 1% compared petrochemical-based plastics, inevitably going significantly near future due strict legislation recently posed by European Union other countries’ Governments. Thus, recycling strategies that have been developed could be disturbed economic balance this sector destabilized. In present review, polymer mainly food packaging, i.e., poly(ethylene terephthalate), PET examined together with its counterparts from poly(lactic acid), PLA (already replacing several applications), poly(3-hydroxybutyrate), PHB furanoate), PEF. Methods chemical these materials products obtained are critically reviewed. Specifically, hydrolysis, alcoholysis glycolysis. Hydrolysis (i.e., reaction water) under different environments (alkaline, acidic, neutral), experimental conditions catalysts results directly corresponding monomers, which however, should separated order re-used re-production respective polymer. Reaction optimized view depolymerize only specific polymer, while others remain intact. Alcoholysis some alcohol, methanol ethanol) methyl ethyl esters diesters again as source producing materials. Glycolysis (reaction glycol, such ethylene, diethylene glycol) much studied PET, whereas less biopolymers seems very promising technique. Oligomers having two terminal hydroxyl groups can further utilized starting value-added products, unsaturated polyester resins, methacrylated crosslinked polyurethanes, etc. These diols derived both bio-based simultaneously without an additional separation step, synthesis final incorporating units structure.