The amphiphilic copolymer poly(hydroxyethyl methacrylate-co-

tert

-butyl methacrylate) [P(HEMA-co-

t

BMA)

]

was synthesized by activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP)

with the synthesis process monitored by

in-situ

infrared spectroscopy (IR). The molecular weight

chemical structure and characteristics of the copolymer were determined by 1H NMR

gas chromatography and gel permeation chromatography. The influences of various parameters on the living polymerization were explored. The molecularweight of the copolymer with narrowmolecularweight distribution (

M

w

/

M

n

b 1.50) increases approximately linearly with the monomer conversion

indicating a good control of polymerization. In the reaction temperature range from 50℃ to 90℃

the monomer conversion is higher at 60℃. The

t

BMA conversion rate decreases gradually with the increase of

t

BMA content

while the HEMA conversion is hardly affected by HEMA content. Weak polar solvent is more favorable to the polymerization compared to polar solvent. The molar ratio of reducing agent to catalyst has significant effect on the polymerization and increasing the amount of reducing age

nt will accelerate the reaction rate but causes wider molecular weight distribution. It is indicated that

in-situ

IR monitoring contributes to a more in-depth understanding of the mechanism of methacrylate monomer copolymerization.