The core-shell p(NIPAM-MAA) microgel was prepared by two-stage process of surfactant-free emulsion polymerization. The first procedure was a reaction of N-isopropylmethacylamide with N,N-methylenebisacrylamide for 3 h in order to obtain seed latexes. In the second stage, the functional monomer MAA was added in the emulsion to sequentially polymerize for 2 h. The objective of this stage was to produce the surface shell layer of microgel. The shape and conformation of gel were determined by transmission electron micrograph and Fourier transform infrared spectroscopy. The temperature- and pH- responsive behaviors were characterized by measuring the diameter of the microgel in aqueous dispersion at different temperature and pH with dynamic light scattering method. Meanwhile, the Zeta potential of microgel was also determined. The results indicated that the morphology of microgel is remarkable core-corona particles. The Zeta potential of microgel particles was related to the size change with temperature and pH.

Key words: N-isopropylmethacylamide, microgel, temperature sensitive, core-corona particle