THE EFFECT OF POLY(N-HYDROXYMETHYL ACRYLAMIDE) CHAIN LENGTH IN POLY(N-VINYL PYRROLIDONE)-BLOCK-POLY(N-HYDROXYMETHYL ACRYLAMIDE) ON ITS SENSITIVITY TO pH

The synthesis of pH-sensitive poly(N-vinyl pyrrolidone)-block-poly(N-hydroxymethyl acrylamide)s (PNVP-b-PNMA) was carried out using atom transfer radical polymerization by varying the amount of N-hydroxymethyl acrylamide to study its effect on pH. The success of polymerization was characterized using FT-IR and¹ H-NMR. The investigation of block copolymers sensitivity to pH was performed by observing the changes in particle sizes of copolymers at various pH. Particle sizes of PNVP-b-PNMA were affected by the pH, in which they became smaller (275.43 – 548.70 nm) at pH 9 and 12 than that in pH 3, 5, and 7 (394.86 – 694.56 nm). In addition, particle sizes increased along with the increasing monomer composition of N-hydroxymethyl acrylamide.