Synthesis and characterization of polyacetals and NMR study on its degradation kinetics

With p-TSA as catalyst, four different types of polyacetals (PA1, PA2, PA3, PA4) were synthesized with amino-protected serinol, tri(ethylene glycol) divinyl ether and PEG2000 in different molar ratios. The structure of the resultant polyacetal was characterized with ¹H NMR. The degradation process of the copolymers was monitored via ¹H NMR in pH = 7.4, 6.5, 5.7 PBS and pH = 4.7, 4.1, 3.8 acetic buffer, respectively. It was found that the degradation reaction in acidic buffer of PA3 obeyed the first order kinetics equation. With decreasing pH values of the buffer solution, the degradation rate constant increases and the half-life decreases.