Microgelation in Free-Radical Crosslinking Polymerization and Copolymerization of Multivinyl Compounds

摘要

Earlier, Staudinger et al. [1] have reported styrene (St)-divinylbenzene (DVB) microgel. Thereafter, numerous reports on the microgel formation have been published in the homopolymerizations of multivinyl compounds and their copolymerizations with monovinyl monomers [2-6]. However, no microgelation was observed in the bulk polymerization of diallyl phthalate giving a quite low primary chain length [7] and also, in the monovinyl-divinyl copolymerizations with only a small amount of divinyl monomer [8]. Thus a detailed study on the microgelation, especially up to the gel point conversion, is required because the microgelation leads not only to the delayed gelation, but also to the microheterogeneity of network structures of three-dimensional polymers as closely related to their properties.