Preparation of temperature sensitive ultrafine particles of poly(N-isopropyl acrylamide) by microemulsion polymerization

The ultrafine particles of linear and cross-linked poly(N-isopropyl acrylamide) were prepared by microemulsion polymerization. The polymerization kinetic equation was derived: R _p = K[M] ^1.16 [E] ^-1.20 [I] ^0.53. The average diameter of ultrafine particles was 100 nm. The structures of the ultrafine particle were studied by SEM and front chromatography techniques. The specific surface area, pore size and adsorbent maximum were 49.048 m ²/g, 1-10 nm and 1784.8 cm ³/g, respectively. The sensitive temperature in water medium was found to be 31.5°C by turbidimetric method and visual method.