Making polymer concrete and polymer mortar using synthesized unsaturated polyester resins from poly(ethylene terephthalate) waste

Abstract

Depolymerization of poly(ethy1ene terephthalate), PET, waste was studied in the presence of manganese acetate catalyst and propylene glycol (PG) at different weight ratios. The glycolyzed products were analyzed for hydroxyl value and the amount of free glycol. A series of unsaturated polyesters based on the glycolyzed products, maleic anhydride and styrene, were prepared. Molecular weights and curing behavior of these polyesters were determined. Polymer concrete (PC) and polymer mortars ( P M ) made with these resins were investigated for their compressive strength. It has been found that the properties of PC and PM obtained from resins based on recycled PET are comparable to PC and PM made from virgin materials.

On the UV Curability and Mechanical Properties of Novel Binder Systems Derived from Poly(ethylene terephthalate) (PET) Waste for Solventless Magnetic Tape Manufacturing, 1. Acrylated Oligoesters

“…The glycolysis reaction was carried out in a continuously stirred three-necked flask equipped with a condenser, thermometer and nitrogen inlet, in order to avoid the oxidation products obtained in presence of atmospheric oxygen and elevated temperature. The temperature of the reaction was kept constant at 200-220 8C for a time period of 4 h. [11][12][13][14][15] After the completion of glycolysis reaction, the product was cooled to room temperature, dissolved in a suitable amount of dichloromethane (CH 2 Cl 2 ), and shaken vigorously with an equal amount of distilled water in order to get rid of unreacted glycol and remaining catalyst. [16,17] After phase separation between the two layers, the organic layer (oligoesters dissolved in organic solvent) was collected and washed several times with distilled water.…”

New Motivation for the Depolymerization Products Derived from Poly(Ethylene Terephthalate) (PET) Waste: a Review

“…Abdel‐Azim et al83,84,135 based his work on the conclusions arrived by Vaidya and Nadkarni and based all the experimental calculations on the same fallacious facts. Abdel‐Azim in his earlier publications83,135 used mixed glycol systems in the glycolysis step and built his calculations on the weight‐to‐weight ratios of the glycol‐PET system instead of the molar ratios.…”

“…Many workers have considered the glycolysis of PET over the last few decades,126–133 but most of the literatures published in this area dealt with the glycolyzed products as mixtures of bishydroxyethyl terephthalate (BHET) and oligomers containing terephthalate repeating units ended with two terminals hydroxyl groups 19,20,22,42,43,48,49,69–72,83,84,134,135. Halacheva et al21 was the first author who suggested a mechanism attributing the formation of internal or secondary hydroxyl groups in the chemical structures of the glycolyzed products.…”

“…UP can be synthesized for this purpose from virgin material65–68 or from recycled products of PET waste 69–76. UP synthesized from PET waste is also applied in making polymer concretes and polymer mortars77–84 and was more recently applied for synthesizing modified UP with improved curing thermal profiles85 and improved mechanical properties 86. Pimpan87 studied the synthesis and curing characteristic behavior of unsaturated polyester resins from post‐consumer PET bottles.…”

Modified unsaturated polyester resins synthesized from poly(ethylene terephthalate) waste, 1. Synthesis and curing characteristics

“…Glycolysis reaction was carried out in a continuously stirred three-necked flask equipped with a condenser. The temperature of the reaction was kept constant at 200 -220 8C for a time of 4 h. [12][13][14][15][16] After completion of the glycolysis reaction, the product is cooled to room temperature, dissolved in a suitable amount of non-polar organic solvent, e. g., CH 2 Cl 2 , CCl 4 or benzene, and shaken vigorously with an equal amount of distilled water in order to get rid of unreacted glycol and remaining catalyst. [17] After phase separation between the two layers, the organic layer (oligomer dissolved in non-polar solvent) is collected and washed several times with distilled water by the same way.…”