The present invention provides a method of preparing a monomer-grafted
syndiotactic polystyrene with polarity, which comprises (a) forming
swollen syndiotactic polystyrene by mixing with a syndiotactic polystyrene
in powder state and a radical initiator in a solvent at the temperature of
40-80.degree. C. using a batch reactor, and (b) grafting a monomer
selected from the group consisting of maleic anhydride, maleic imide and
derivatives thereof onto the swollen syndiotactic polystyrene.
