Investigation of the effect of hydrolysis products of postconsumer polyethylene terephthalate bottles on the properties of alkyd resins

Abstract

Hydrolysis of waste polyethylene terephthalate (PET) flakes obtained from grinding postconsumer bottles was carried out at 200230 degrees C and molar ratios of PET/H2O were taken as 1/5; 1/10; 1/20. The reaction products, when extracted with boiling water, yielded a water soluble crystallizable fraction (WSCF) and a water insoluble fraction (WIF). These fractions were characterized by acid and hydroxyl value determinations and DSC analysis. WSCF and WIF were used for preparation of alkyd resins. Five long oil alkyd resins were prepared from phthalic anhydride (PA) (reference alkyd resin) or hydrolysis products of the waste PET (PET-based alkyd resin), pentaerithrithol (PE), soybean oil fatty acid (SOFA), and ethylene glycol (EG). Film properties and thermal degradation stabilities of these alkyd resins were investigated. Drying time, hardness, alkaline resistance, and thermal oxidative degradation resistance of the PET-based alkyd resins are better than these properties of reference resin. The results show that hydrolysis products of waste PET obtained from postconsumer bottles are suitable for manufacturing of alkyd resins. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers