The effect of xylene as aromatic solvent to aminoglycolysis of post consumer PET bottles

Abstract

This study deals with the use of ethylene glycol and diethylamine for the aminoglycolytic degradation of waste poly(ethylene terephthalate) (PET). Our aim is to investigate how the product composition changes according to depolymerization conditions and to obtain oligomer mixtures having different properties. For this purpose, simultaneous aminolysis–glycolysis reactions of postconsumer soft‐drink PET bottles were carried out in a high pressure reactor with or without xylene. As a result, the oligomer mixtures having carboxyl, hydroxyl, and amine end groups were obtained at the end of the aminoglycolysis of PET. All products were characterized by acid value, hydroxyl value, and amine value determinations as well as by Fourier Transform Infrared Spectroscopy and Differential Scanning Calorimeter. Use of xylene has provided initially easily mixable low viscosity dispersions and depolymerization reactions proceeded more easily. It also provided water soluble and lower molecular weight oligomers with deep depolymerization of PET in the presence of xylene. In case of using xylene, glycolysis reaction was dominant reaction rather than aminolysis and hydrolysis. Functional oligomer mixtures obtained from degradation of waste PET can be used for synthesis of coating materials, such as water reducible alkyd resins and epoxy resins. POLYM. ENG. SCI., 53:2429–2438, 2013. © 2013 Society of Plastics Engineers

Influence of a Catalyst in Obtaining a Post-Consumer Pet-Based Alkyd Resin That Meets Circular Economy Principles

“…Figure 4a shows the peaks characteristic of post-consumer PET, whose main bands are 1714 cm −1 for the C=O group; between 1099 and 1244 cm −1 for the COOC; group; and 723 cm −1 for aromatic-H, results also observed in the literature [10,76,77].…”

Preparation and characterization of waterborne alkyd-amino baking coatings based on waste polyethylene terephthalate

“…PET containing ester groups can be hydrolysed [5], alcoholized [6], glycolyzed [7][8][9][10][11][12] and ammonolysed [13][14][15][16] in the presence of water, alcohol, glycols and amines. Glycolysis is an important and commercial process for the chemical depolymerization of PET.…”

The use of aminolysis, aminoglycolysis, and simultaneous aminolysis–hydrolysis products of waste PET for production of paint binder

“…Therefore, recycling of waste PET has emerged as a necessity due to environmental factors . There are four main approaches for recycling of waste PET, namely primary, secondary, tertiary or chemical, and quaternary recycling . Among these methods of PET recycling, chemical recycling is the most preferred method.…”

“…The chemical recycling of PET is carried out with the aim of obtaining either its monomers such as terephthalic acid (TPA), ethylene glycol (EG), and bis(2‐hydroxyethyl terephthalate) (BHET), or higher molecular weight intermediates suitable for preparing other polymers . The chemical recycling of waste PET can be carried out in many ways such as glycolysis, hydrolysis, alcoholysis, simultaneous hydrolysis–glycolysis, aminolysis, and aminoglycolysis . The PET monomers can be obtained by acidic, neutral, and alkaline hydrolysis or glycolysis.…”

“…In addition, there are few studies about aminolysis reactions of waste PET . According to the technical literature, there is no research about the depolymerization reaction of waste PET with amines at “high pressures” except our previous articles . In mentioned studies, aminoglycolysis products of waste PET were evaluated as “polyurethane coating material” , “water reducible alkyd resin” , and “low cost adsorbent for the removal of basic dyes from wastewaters” .…”