Study on Rosin Polyester Polyol Modified by Recycled Terephthalic Acid

The synthesis technique and properties of rosin polyester polyol modified by terephthalic acid was studied.The factors such as dosage of terephthalic acid,reaction time,reaction temperature and dosage of catalyst were investigated.The structure of rosin polyester polyol modified by terephthalic acid was characterized by infrared spectroscopy and chemical analysis.The pro-ducts with properties of acid value ≤5 mg/g,hydoxy value 380-420 mg/g and viscocity 5.5-6.5 Pa·s was obtained under conditions of rosin 105 g,terephthalic acid 45 g,diethylene glycol 150 g,catalyst 0.5 g,reaction temperature 250 ℃ and reaction time 7 h.Comparing with the traditional rosin polyester polyol technology,the eserification time was reduced from 9 h to 7 h by adding the terephthalic acid.The application test showed that the properties of the modified rosin polyol foam reached the standard of GB/T 20219-2006.