Organosoluble Oligomer Obtained by Glycolysis of Poly(ethylene terephthalate) and Its Detailed Structural Characterization by MALDI-TOF Mass Spectrometry

Abstract

ABSTRACT:Organosoluble oligomers were obtained by the depolymerization of poly(ethylene terephthalate) with an aliphatic glycol at 260-280• C and then characterized by 1 H NMR, gel permeation chromatography (GPC), and matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS). The detailed analysis of their spectrum revealed that for an aliphatic primary diol, the transesterification smoothly occurred in the reaction media.KEY WORDS Poly(ethylene terephthalate) / Glycolysis / Organosoluble Oligomer / MALDI-TOF Mass Spectrometry / Poly(ethylene terephthalate), PET, is widely used for synthetic fibers and film and recently its use in the production of soft drink bottles has been dramatically increasing. The efficient utilization of waste PET resulting from its huge production is a very important issue and there has been a growing tendency to effectively recycle it. PET possessing an ester linkage is a suitable material for feedstock recycling and many methods using chemical degradation have already been reported, 1,2 along with that of mechanical recycling. The recycling methods are mainly divided into alcoholysis (methanolysis and glycolysis) and hydrolysis, and the methanolysis process which produces dimethyl terephthalate (DMT) and ethylene glycol (EG) has already been adopted in some companies. The glycolysis process has been also well studied using EG to obtain bis-hydroxyethyl terephthalate (BHET) which can be used as a substrate for PET synthesis. Partial PET glycolysis depending on the ratio between the PET and glycol, reaction time, and reaction temperature is also an important process and the process using EG as a glycol usually produces BHET and oligomers having molecular weights less than 1000, both of which are quite useful materials for the synthesis of unsaturated polyesters and polyurethanes. 3 Recently, as a new entry for the useful utilization of the glycolysis products, we have demonstrated the synthesis of a copolyester by polycondensation between the glycolysis products and copoly(succinic anhydride-ethylene oxide). 4 We have also reported as a patent that various vinyl-terminated macromonomers, which would be useful for paintings, adhesives, and so on, were synthesized from the glycolysis products. 5 For the design and synthesis of the † To whom correspondence should be addressed.

Study of Polyurethane Formulations Containing Diols Obtained via Glycolysis of Poly(ethylene terephthalate) (PET) by Oligoesters Diols through a Reactive Extrusion Process

“…Marechal10 studied the polyurethane foam synthesis containing glycolysates as well as the heat and acoustical insulation properties of these foams. In most cases, the PET is glycolysated by a diol11 of one of the following types: ethylene glycol (EG),12–14 diethylene glycol (DEG),15,16 butanediol,17,18 propylene glycol 19. The oligomers obtained are crystalline, and storage problems appear.…”

Study of the glycolysis of PET by oligoesters

“…Mori [36] and Dannoux [14] studied by MALDI-TOF the glycolysis of PET with one diol where two principal repeating units were noticed. In this paper, we studied the glycolysis by oligoesters with four different units.…”

Water-assisted single-step catalytic hydrodeoxygenation of polyethylene terephthalate into gasoline- and jet fuel-range cycloalkanes over supported Ru catalysts in a biphasic system

“…Various chemical upcycling methods have recently been reported, including gasification, pyro-, glyco-, hydro-, methano-, ammonolysis, and hydrosilylation. [14][15][16][17] However, these methods suffer from harsh reaction conditions, low benefits, high costs, and secondary pollution. Therefore, developing cost-effective, green, efficient approaches for use in upcycling waste PET into fuel-range hydrocarbons is an innovative solution.…”