Jian KANG, Feng YANG, Jin-yao CHEN, Ya CAO, Hui-lin LI, Ming XIANG. Application and Optimization of Successive Self-nucleation and Annealing Fractionation on the Analysis of iPP Tacticity[J]. Polymer Bulletin, 2013,26(9):168-176.
Jian KANG, Feng YANG, Jin-yao CHEN, Ya CAO, Hui-lin LI, Ming XIANG. Application and Optimization of Successive Self-nucleation and Annealing Fractionation on the Analysis of iPP Tacticity[J]. Polymer Bulletin, 2013,26(9):168-176.DOI:
high efficiency and relative low cost of the required instruments
Successive Self-nucleation and Annealing (SSA) fractionation has been widely applied in the analysis of ethylene/α-olefin copolymers. However
it has rarely been successfully applied in the analysis of PP. In this study
the self-nucleation behavior of PP had been studied. Based on the results
obtained
a SSA thermal protocol for
i
PP was designed
and the influence of important parameters (the first thermal treatment temperature T
s1
; holding time t
s
; temperature gap between adjacent T
s
ΔT; fractionation temperature region) on the fractionation results and efficiency
were thoroughly studied. The results showed that
for
i
PP samples
the optimal thermal parameters are T
s1
=167℃
t
s
=15min
ΔT=4℃
cooling/heating rate=20℃/min
fractionation temperature region=167-139℃. The variation of fractionation temperature region plays a most important role in determining the efficiency of SSA. For iPP with different tacticity
one must flexibly modify the parameters above
to achieve a balance between efficiency and fractionation results.