Syndiotactic polystyrene was synthesized by emulsion polymerization using Ni(COD)2 and ligands containing P and O as catalyst.The reaction kinetics of the above process was studied.The product was characterized with 13C-NMR

1H-NMR

GPC

TEM

DSC and TG etc.The best polymerization condition for this reaction system was found to be:emulsifier 1.50 g

[St]0=1.79 molL-1

T=60℃

t=2 h

[Ni(COD)2] =1.10 mmolL-1

the conversion was 78%.The activity of the catalyst was 662.14 gPS(gNih)-1.The emulsion particle size was 100~120 nm from the results of particle size analysis and TEM techniques.Very good thermal stabilities of latex are observed in the temperature range of ambient temperature up to ca. 376℃.The GPC analysis results show that:the weight average molecular weight Mw is 1.64106

while the number-average molecular weight Mn is 9.79105 and the width of molecular weight distribution is 1.6. The 13C-NMR

1H-NMR and TG analysis results proved the syndiotactic structure.The polymers exhibit glass transition temperature of Tg=114.95℃.The rate of polymerization (Rp) was found to be dependent on the monomer

catalysts concentrations.Preliminary study on the kinetics of the polymerization indicates that:the apparent activation energy Ea is 20.76 kJ/mol

the rate equations are:Rp=1.687[St]0.241[Ni(COD)2]0.542(when [St]1.79 molL-1)

Rp=0.03683[St]-0.187[Ni(COD)2]0.542 (when [St]1.79 molL-1).