writer：Li, DF,Li, SH,Wu, CJ,Yao, CG,Cui, DM
keywords：Rare earth metal complex,Ethylene,Propylene,Copolymerization
source：期刊
specific source：http://pub.chinasciencejournal.com/ActaPolymericaSinica/25357.jhtml
Issue time：2013年

The scandium dialkyl complex LSc(CH₂SiMe₃)₂ (L=(2,6-ⁱPr₂C₆H₃)NC(Me)CHPPh₂N-(2,6-Me₂C₆H₃)) activated with [Ph₃C][B(C₆F₅)₄] could initiate ethylene and propylene copolymerization with high activity (7.5×10⁵g(PE)mol^-1 h^-1 (10⁵Pa)^-1) under the conditions of room temperature (30 ℃) and atomphere pressure (1.0 × 10⁵ Pa).The influence of comonomer feed content and polymerization temperature on activity and the composition of the copolymers using LSc(CH₂SiMe₃)₂/[Ph₃C][B(C₆F₅)₄] catalytic system were investigated.An increase in the initial propylene feed content leads to the increase in the incorporated propylene content of the resulting copolymer.At 30 ℃,the highest activity and incorporation of propylene were achieved.Determination of the reactivity ratios shows a much high reactivity for ethylene (r_E=29.75 and r_P=0.015).The resultant copolymers are elastomers having random sequence distibution of the two monomeric units evidenced by ¹³C-NMR spectroscopy and DSC analyses.