Journal of Polymers

Research Article

Intramolecular Lactonization of Poly(α-hydroxyacrylic acid): Kinetics and Reaction Mechanism

Table 2

Effect of pH on the rate constants of lactone ring formation ((close)) and opening ((open)) and the relative standard error of the rate constants as well as the corresponding equilibrium conversion () for PHA lactonization at = 24.7 ± 0.7°C.
pH(close)Standard error(open)Standard error
s−1(close) %s−1(open) % ((close))/(open))%
11.14 × 10−4 3.2 4.54 × 10−5 5.22.5171.5
21.09 × 10−4 3.5 4.46 × 10−5 6.82.4470.9
31.91 × 10−4 3.3 5.43 × 10−5 4.83.5277.9
41.71 × 10−4 4.5 8.13 × 10−5 6.62.1067.7
4.51.78 × 10−4 6.28.38 × 10−5 9.52.1267.9
58.92 × 10−5 6.68.36 × 10−5 8.71.0751.7
64.52 × 10−5 11.07.91 × 10−5 13.40.57 36.3