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

Abstract

Poly(ethylene terephthalate) (PET) from off‐grades of industrial manufacturers was partially and thoroughly depolymerized in order to synthesize PET oligomers and bis(hydroxyethyl) terephthalate (BHET), respectively. Design of experiments and analysis of variance (ANOVA) were applied for optimization of samples. Effects of reaction time, volume of glycol, catalyst concentrations, and particle size of off‐grade PET were investigated. The optimal conditions to synthesize PET oligomers (3–8 repeating units) were glycol/PET molar ratio of 1, a weight ratio (catalyst to PET) of 0.5 wt%, using granule‐shape. On the other hand, a reaction time of 180 min, a weight ratio (catalyst to PET) of 0.25 wt%, and glycol/PET molar ratio of 5 were obtained as the suitable conditions of BHET production. Then, endcapped PET oligomers, as a compatibilizer for preparing PET nanocomposites, were produced via reaction between maleic anhydride/phthalic anhydride (MA/PhA) composition. The combination of reaction time of 106 min and PhA/MA molar ratio of 0.85 produced the best results based on d‐spacing and peak shift of nanocomposite samples. Moreover, the reaction of MA and BHET from glycolyzation of PET was successfully performed at 160°C and 190°C for 8 h. The optimum conditions were compared with a synthesized PET. POLYM. ENG. SCI., 54:417–429, 2014. © 2013 Society of Plastics Engineers

Effect of the modified silica Nanofiller on the Mechanical Properties of Unsaturated Polyester Resins Based on Recycled Polyethylene Terephthalate

“…The nucleophilicity of the hydroxyl group was suppressed in that way, and thus retardation of the reaction rate was observed. Zahedi et al defined the optimal glycolysis conditions of amorphous off grade PET using response surface method. They illustrated the influences of glycolysis time, molar ratio of EG and PET, and the amount of catalyst, that is, zinc acetate dihydrate.…”

RETRACTED: Chemical recycling of Poly (Ethylene Terephthalate) waste as a sustainable source for synthesis of unsaturated polyester resins

“…Several methods of chemical recycling of PET have been suggested since they produce a variety of ultimate products, which can be classified into the following categories: Methanolysis, glycolysis, hydrolysis, ammonolysis, aminolysis, and other reactions are among them. Glycolysis and methanolysis are mostly used in industry [9]. The most promising option, however, is glycolysis, which produces similar monomers or raw materials that could be utilized again to produce plastic or other advanced materials.The glycolysis of PET waste with glycols in the presence of a suitable catalyst yields terephthalic oligomers by transesterification.…”

Montmorillonite-reinforced nanocomposite from off-grade plastics materials using response surface analysis

“…In previous studies, a simple glycolysis system was set up in the presence of zinc acetate, as an efficient catalyst, and the glycolyzed products of off-grade PET were identified. 10,[31][32][33][34] There has also been an increase in demand for the production of oligomeric intermediate yields using PET waste. 35 However, no report has been published for depolymerizing offgrade PET by partial glycolysis method in order to synthesize oligomers for applying in nanocomposite materials.…”