Cyclodextrins (CD)

characterized by their biocompatibility

environmental amity

and low price

have been used in many fields.In recent years

their application in polymer chemistry attracts great attention.In this paper

using styrene as monomer

K2S2O8 as initiator

we investigated the influence of β-CD on the soap-free emulsion polymerization of styrene.It is found that the addition of β-CD can greatly accelerate the polymerization

and increase the monomer conversion.With increase of the amount of CD

the reaction rate also increases.After 5 h

the monomer conversion

in absence of CD

is only 60.3%

which is much lower than that in presence of 1.0 g CD(90%).The final polymer particle-size distribution was more uniform than that without β-CD.The kinetic analysis indicated that β-CD could increase the monomer relative reactivity.AS the ratio of CD/monomer reaches 0.2

the monomer relative reactivity is more than 3 times of that in absence of CD.