Aminoglycolysis of waste poly(ethylene terephthalate) with diethanolamine and evaluation of the products as polyurethane surface coating materials

Abstract

Aminoglycolysis and simultaneous hydrolysis-aminoglycolysis of poly(ethylene terephthalate) (PET) wastes by diethanolamine (DEA) was attempted in the presence of xylene, with the aim of obtaining intermediates containing both hydroxyl and carboxyl end groups, which could be employed in polyurethane surface coatings. Aminoglycolysis and simultaneous hydrolysis-aminoglycolysis reactions were carried out with the catalysis of zinc acetate (ZnAc) at high temperatures and relatively high pressures. Depolymerization products were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimeter (DSC). To prepare polyurethane surface coating films, the depolymerization products were reacted with 1,4 butanediol (BDO) and toluene diisocyanate (TDI) in the presence of dibutiltin dilaurate (DBTDL) catalyst and pyrogallol inhibitor. After the films prepared, the physical properties such as hardness, drying degree, adhesion, and impact resistance of these films were investigated. The intermediates yielded from medium to very hard coatings with excellent adhesion and having medium to very good drying degree. POLYM. ENG. SCI., 51:746-754, 2011. ª 2011 Society of Plastics Engineers EXPERIMENTAL MaterialsWaste PET flakes obtained from grinding of postconsumer bottles (containing 0.3% (w) humidity) were sieved to obtain a 4-to 8-mesh fraction. The viscosity average

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

“…The chemical agents, which can be used to depolymerization of PET, include water, methanol, ethylene glycol, or other glycols such as diethylene glycol and butanediol . 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 .…”

“…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” .…”

“…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” . However, different applications about the evaluating of depolymerization products of PET exist in the literature.…”

Optimization of phthalic/maleic anhydride-endcapped PET oligomers using response surface method

“…Among all different recycling techniques including chemical, mechanical, and thermal recycling, the most suitable method based on "Sustainable Development" is the chemical recycling, simply because it yields raw materials and other value‐added crops from polymer waste . The chemical degradation processes of PET waste are frequently demonstrated as follows: hydrolysis , glycolysis , methanolysis , aminolysis , ammonolysis , and other processes . Glycolysis and methanolysis are commercially used; however, the most interesting one is the glycolysis method that yields related monomers or raw materials that could be reused for plastics production or other advanced materials .…”

Heterotrophs grown on the soluble microbial products (SMP) released by autotrophs are responsible for the nitrogen loss in nitrifying granular sludge

“…Chemical recycling processes can result in total depolymerization to the monomers or partial depolymerization to the oligomers [1]. Chemical recycling processes of waste PET can be classified under different main headings such as hydrolysis [10, 12–15], glycolysis [8, 16], simultaneous hydrolysis‐glycolysis [17], aminolysis [18–20], and aminoglycolysis [19, 21]. Recycling methods of waste PET have been reviewed by Karayannidis and Achilias [9].…”