The effect of oleates as emulsifiers on graft copolymerization of starch with acrylamide (AM) and acrylic acid (AA) in the inverse emulsion system is studied in this paper .The effect of the kinds of emulsifiers

the proportion of mixed emulsifiers

the dosage of emulsifiers as well as the preparation methods of water-in-oil emulsion on monomer conversion

grafting ratio

and specific viscidity is discussed. The result indicates that calcium oleate or magnesium oleate as the emulsifier is better than sodium oleate or potassium oleate

and the mixture of oleic acid and its salt is better than any single compound.It is also concluded that monomer conversion reaches 99.7% and grafting ratio reaches 98.4% when m(oleic acid)/m(ol eate sodium) is 60/40

m(starch)/m(monomers) is 1/1(among the monomers m(AM)/m(AA) is 4/1)

v(oil phase)/v(water phase) is 1.2/1

initiator concentration is 2.4×10-4mol8226;L-1

reaction temperature is 45～50℃

and reaction time is 6 hours.When mixed emulsifers concentration is 6%

the intrinsic viscidity reaches 1100ml8226;g-1.