Polymerization of AM inverse microemulsion initiated directly by UV radiation

By combining the microemulsion polymerization with UV direct initiation, an efficient method for polymerization of AM with high polymerization rate and purity of product, low polymerization temperature and viscosity was developed. In the absence of initiator and under UV radiation, the polymerizations of AM inverse microemulsion system were successfully accomplished at low temperature (24°C~30°C) and PAM microlatex was obtained. The effects of UV intensity, monomer concentration, emulsifier concentration and temperature on polymerization rate and intrinsic viscosity of polymer were researched. R _p decreased with [E] and increased with I _UV, [M] and T. [η] increased with [M] and decreased with I _UV, [E] and T. The apparent activation energy of the reaction and polymerization kinetics of R _p was obtained as the following: E _a=12.98 kJ/mol, R _p∝[I _UV] ^0.4972 [M] ^1.5048 [E] ^-0.5731. Based on the abundant experimental results, the reasonable polymerization mechanisms were proposed.