Supercritical Carbon Dioxide-Assisted Dispersion of Sodium Benzoate in Polypropylene and Crystallization Behavior of the Resulting Polypropylene
作者:Bin Li,1 Guo-Hua Hu,2,3 Gui-Ping Cao,1 Tao Liu,1 Ling Zhao,1 Wei-Kang Yuan1
关键字:supercritical carbon dioxide,polypropylene,sodium benzoate,dispersion
论文来源:期刊
发表时间:2006年
This work aimed at studying the efficiency of
the use of supercritical carbon dioxide (scCO2) as a swelling
agent to disperse sodiumbenzoate (NaBz), a nucleating agent,
in polypropylene (PP), on the one hand; and the crystallization
behavior of the resulting PP, on the other hand. Under scCO2,
the NaBz was uniformly dispersed in the PP at a nanometer
scale. The use of ethanol or acetone as a cosolvent further
increased its state of dispersion and its mass uptake in the PP.
Isothermal and nonisothermal crystallization kinetics indicated
that the PP with the NaBz being dispersed in it under
scCO2 had a much higher crystallization rate than that of the
pure PP or the PPwith the NaBz being dispersed in it by a conventional
melt compounding process. The size of the PP crystallites
was also much smaller when the NaBz was dispersed
at a nanometer scale.