One-Pot Synthesis of Arborescent Polystyrenes
Zhongshun Yuan
Mario Gauthier
10.1021/ma051123c.s001
https://acs.figshare.com/articles/journal_contribution/One_Pot_Synthesis_of_Arborescent_Polystyrenes/3232012
A new grafting-from procedure was developed for the synthesis of arborescent styrene polymers
of successive generations in a single reaction pot. Styrene was first copolymerized anionically in a semibatch
process with 1,3-diisopropenylbenzene (DIB), and the chains were terminated with methanol. The pendent
isopropenyl moieties of the DIB units were then reacted with <i>sec</i>-butyllithium to generate a polyfunctional anionic
macroinitiator. Further additions of styrene−DIB monomer mixture to the activated linear substrate yielded a
comb-branched (generation G0) copolymer. After termination of the chain ends and activation of the double
bonds on the G0 substrate, styrene monomer was added to generate G1 arborescent polystyrenes, with a dendritic
architecture. Alternately, the G0 copolymer was isolated by precipitation and activated in a separate procedure.
The size (molecular weight) of the side chains in the G1 polymer was conveniently controlled by varying the
amount of monomer added to the G0 macroinitiator. The reaction conditions were optimized to obtain graft
polymers with relatively low polydispersity indices (<i>M</i><sub>w</sub>/<i>M</i><sub>n</sub> = 1.1−1.3) and absolute weight-average molecular
weights <i>M</i><sub>w</sub> reaching 7 × 10<sup>6</sup>. The intrinsic viscosity in toluene of the arborescent G1 polystyrenes synthesized
was up to 7.2 times lower than for linear polystyrene samples of comparable molecular weight.
2006-03-21 00:00:00
arborescent styrene polymers
reaction pot
pendent isopropenyl moieties
weights M
polydispersity indices
dendritic architecture
generation
graft polymers
chain ends
G 1 arborescent polystyrenes
G 0 macroinitiator
copolymerized anionically
arborescent G 1 polystyrenes
G 0 copolymer
DIB units
G 0 substrate
polystyrene samples
G 1 polymer
semibatch process
7.2 times
procedure
reaction conditions
Arborescent Polystyrenes
side chains
styrene monomer