Author/Authors :
Zhao، Ning نويسنده , , Cheng، Ruihua نويسنده State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China , , Dong، Qi نويسنده , , He، Xuelian نويسنده State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China , , Liu، Zhen نويسنده State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China , , Zhang، Shiliang نويسنده State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China , , Terano، Minoru نويسنده , , Liu، Boping نويسنده ,
Abstract :
SiO2-supported silyl chromate catalyst is an important industrial catalyst for production of high grade HDPE
pipe materials. The control of the short chain branch (SCB) distribution using this catalyst system is still a great
challenge. In this work, ethylene and 1-hexene copolymers were synthesized using SiO2-supported silyl chromate
catalyst combined with triisobutylaluminium (TIBA), triethylaluminium (TEA) and mixed TIBA/TEA at molar
ratio 1:1 (TIBA/TEA/1:1) as three different Al-alkyl co-catalysts.The temperature rising elution fractionation
(TREF) and successive self-nucleation and annealing (SSA, by DSC) methods were combined to analyze the short
chain branch distribution (SCBD) of these ethylene/1-hexene copolymers. The results showed that different types
of co-catalyst had a great influence on SCBD of ethylene/1-hexene copolymers. The copolymer produced with
TIBA showed better SCBD than the copolymer produced with TEA, and the copolymer produced with TIBA/
TEA/1:1 showed a SCBD in between those with TIBA and TEA.
