For the first time

a water-swellable rubber

poly(natural rubber-g -acrylamide)

was prepared quickly by frontal polymerization.Compared with batch polymerization

the front polymerization process was studied and the polymers were characterized.The frontal polymerization reaction is ignited after the system temperature is higher than 45 ℃ approximately.As important process parameters

the frontal temperature is about 112 ℃ while the front velocity is between 0.3 cmmin-1 and 1.0 cmmin-1.The grafting efficiency of frontal polymerization is 51.8% which is 2.8 times as much as that of batch polymerization.The maximum water absorption of products prepared via FP was calculated as 7.66 gg-1 which is 60% higher than that of the batch polymerization.While the reaction time of frontal polymerization is an eighth of the reaction time of batch polymerization.The microstructure of water-swellable rubber synthesized by frontal polymerization was studied.The relatively uniform hollows

at a size range from 4 m to 10 m

can improve the swelling ability while keep the good strength and elasticity.While the batch polymerization polymers have a lots of holes less than 2 m and sporadic linear holes near 1 mm.