Kinetics of polycondensation and copolycondensation of Bis(3-hydroxypropyl terephthalate) and Bis(2-hydroxyethyl terephthalate)

✍ Scribed by Joon Ho Kim; Sang Yong Lee; Jun Ho Park; Won Seok Lyoo; Seok Kyun Noh

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 147 KB
• Volume: 77
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(20000718)77:3<693::aid-app24>3.0.co;2-q

✦ Synopsis

The kinetics of polycondensation and copolycondensation reactions of bis(3hydroxypropyl) terephthalate (BHPT) and bis(2-hydroxyethyl) terephthalate (BHET) as monomers were investigated at 270°C, in the presence of titanium tetrabutoxide (TBT) as a catalyst. BHPT was prepared by ester interchange reaction of dimethyl terephthalate (DMT) and 1,3-propanediol (PD). Applying second-order kinetics for polycondensation, the rate constants of polycondensation of BHPT and BHET, k 11 and k 22 , were calculated as 3.975 and 2.055 min Ϫ1 , respectively. The rate constants of cross-reactions in the copolycondensation of BHPT and BHET, k 12 and k 21 , were obtained by using the results obtained from a proton nuclear magnetic resonance spectroscopy. The rate constants during the copolycondensation of BHPT and BHET at 270°C decreased in the order k 11 Ͼ k 12 Ͼ k 22 Ͼ k 21 , indicating the block nature of the copolycondensation.