A novel method was developed to polymerize acrylamide in an opaque inverse emulsion system by UV light initiation

which was usually used in a transparent system or semi-transparent system

such as solution systems and micro-emulsion systems．Using 2

2-Dimethoxy-2-phenylacetophenone (DMPA) as an initiator

Span80+OP10 as a blend emulsifier

the inverse emulsion polymerization of acrylamide in kerosene could be completed in about 20 min with exposure under a medium pressure mercury lamp and proper mixing

and the molecular weight of the produced polymer was as high as 107. No constant polymerization rate period was observed throughout the whole polymerization process

and there was no dramatic difference between the size of the initial monomer droplets and the size of the final inverse latexes according to scanning electron microscope observation

indicating that the polymerization was nucleated inside the monomer droplets．The influences of the type and concentration of photoinitiator

monomer concentration

emulsifier percentage and reaction temperature on polymerization were investigated．The initiating activity of photoinitiators is in an order of Irgacure 2959 ＞ (ITX+EDAB) ＞ BDK．When the concentration of photoinitiator increases

the reaction rate increases at first

then begins to decrease after the reaction rate reaches a maximum value．Both the reaction rate and the molecular weight increase when the monomer concentration increases．With the increase of the emulsifier percent age the reaction rate increases

while no dramatic change displays in the molecular weight．The overall activation energy of polymerization was measured as 13.34 kJ／mol.