H. Oike et al., A cyclic macromonomer designed for a novel polymer network architecture having both covalent and physical linkages, MACROMOLEC, 34(18), 2001, pp. 6229-6234
A methacrylate-functionalized, cyclic poly(tetrahydrofuran), poly(THF) (1m)
, has been synthesized and copolymerized through a free-radical mechanism i
nvolving methyl methacrylate (MMA) and using 2,2 ' -azobisisobutyronitrile
as the initiator in benzene at 65 degreesC. A copolymer product with cyclic
poly(THF) branches was produced initially, with gelation taking place at a
later stage of the reaction. In contrast, no gelation was observed either
in the quantitative-conversion copolymerization of a related methacrylate-f
unctionalized, open-chain poly(THF) with MMA or in the quantitative homopol
ymerization of MMA in the presence of a methacrylate-free, cyclic poly(THF)
. These results demonstrate that the propagating polymer segment threaded t
he large but constrained cyclic polymer branches covalently attached to the
polymer backbone, to produce a novel polymer network architecture having b
oth covalent and physical linkages.