Polymerization of styrene with a simple rare earth metal initiator

Abstract

The catalytic activity in the polymerization of styrene has been examined using commercially available simple rare earth metal compounds such as Sm(OiPr) 3 , Sm(acac) 3 , Sm(OCOMe) 3 , SmI 2 (THF) 2 or SmCl 3 coupled with Et 3 Al or methylaluminoxane (MAO). Among these compounds, the Sm(OiPr) 3 /AlEt 3 system shows the highest catalytic activity, especially in the presence of a minor amount of toluene at 60°C. The random copolymerization of styrene with methyl methacrylate suggests that the present polymerization proceeds with a radical polymerization mechanism. (C 5 Me 5 )SmCl 3 Na(THF) and (C 5 Me 5 )SmCl 3 Li(THF) systems exhibit relatively low catalytic activity, even in the presence of AlEt 3 .

Reversible coordinative chain transfer polymerization of styrene by rare earth borohydrides, chlorides/dialkylmagnesium systems

“…The 1 H‐NMR spectra of 1 in benzene‐ d 6 in the presence of styrene further indicates the absence of a reaction. The neodymium trisborohydride 1 is not active as a single‐component for the polymerization of styrene, a behavior similar to that of lanthanide chlorides: samarium trichloride has been reported to be inactive by itself for the polymerization of styrene17 but active in the presence of a cocatalyst 18…”