Preparation of Poly(ethyleneglycol-co-acrylic acid) Nanospheres with Divinylbenzne as Crosslinker by Distillation-precipitation Polymerization
作者：Zhao Dai, Xinlin Yang*, Wenqiang Huang*
關鍵字：Distillation precipitation polymerization, Morphology
論文來源：期刊
具體來源：Chin. J. Polym. Sci., 25 (3), 303-309 (2007).
發表時間：2007年
Monodisperse
poly(poly(ethyleneglycol) methyl ether acrylate-co-acrylic acid) (poly(PEGMA-co-AA))
microspheres were prepared by distillation-precipitation polymerization with
divinylbenzene (DVB) as crosslinker with 2,2￠-azobisisobutyronitrile
(AIBN) as initiator in neat acetonitrile without stirring. Under various
reaction conditions, four distinct morphologies including the sol,
microemulsion, microgels and microspheres were formed during the distillation
of the solvent from the reaction system. A 2D morphological map was established
as a function of crosslinker concentration and the polar monomer AA
concentration in comonomer feed on the transition between the morphology
domains. The effect of the covalent crosslinker DVB on
the morphology of the polymer network was investigated in detail at AA fraction
of 40 vol%. The ratios of acid to ethylene oxide group presenting in the
comonomers dramatically affected the polymer-polymer interaction and hence the
morphology of the resultant polymer network. The covalent crosslinking by DVB
and the hydrogen-bonding crosslinking between two acid units as well as between
the acid and ethylene oxide unit played key roles for the formation of
monodisperse polymer microspheres.