Preparation of oligoester diols by alcoholytic destruction of poly(ethylene terephthalate)

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.…”

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

“…This fact confirms that the molar ratio of DEG : PET plays an important role in determining the nature of the obtained gylcolysates. [24] Molecular weight determination Molecular weights of all synthesized unsaturated polyester resins (UP1-UP12) are determined by end-group analysis. [12] Each UP is analyzed for both acid number (A) and hydroxyl value (B) in mg KOH/g, and the numberaverage molecular weight M -n is then calculated from Eq.…”

“…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.…”

“…[22] Each unsaturated polyester resin (UP1-UP12) is dissolved in 40 wt.-% styrene, which acts as a solvent and a crosslinker for these unsaturated polyesters. [24] The products of the glycolysis reaction (glycolysates) were analyzed for hydroxyl values, and these values were applied for the calculation of M -n [22,23] as shown in Tab. 1.…”

“…The wastes from PET spinning are not suitable for a second drawing, so one possible approach to their reuse consists in their transformation into oligoester polyols by alcoholytic destruction. [1][2][3][4][5][6][7] In 1987, the volume of PET consumed in the beverage industry alone was more than 700 million pounds, corresponding to 3 billion bottles. [8] To ease the burden of waste disposal, it is critical that PET polymer is recycled.…”