EFFECT OF β-CYCLODEXTRIN ON SOAP-FREE EMULSION POLYMERIZATION OF STYRENE

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,K_2S_2O_8 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.