The conventional free radical polymerization(FRP) of multivinyl monomers(MVMs) inevitably leads to gelation even at low monomer conversion resulting in difficulties to control and monitor the reaction process. Flory a...The conventional free radical polymerization(FRP) of multivinyl monomers(MVMs) inevitably leads to gelation even at low monomer conversion resulting in difficulties to control and monitor the reaction process. Flory and Stockmayer(F-S theory)studied it based on two fundamental assumptions:(1) independent and equivalent vinyl groups;(2) no intramolecular cyclization.However, until now its applicability to FRP of MVMs(especially regarding the extent of intramolecular cyclization) is still controversial. In this paper, Monte Carlo simulations are used to study FRP of divinyl monomers by two kinetic models:with/without cyclization models. The results of the simulations are compared with the calculated gel points based on F-S theory and the experimental data. It is found that the intramolecular cyclization has a negligible impact on the polymerization process and the gel point before gelation, which are in agreement with the prediction by F-S theory, but the effect becomes significant above the gel points.展开更多
基金supported by the National Natural Science Foundation of China(51573129)Science Foundation Ireland Principal Investigator Award(13/IA/1962)+1 种基金Investigator Award(12/IP/1688)Health Research Board(HRA-POR-2013-412)
文摘The conventional free radical polymerization(FRP) of multivinyl monomers(MVMs) inevitably leads to gelation even at low monomer conversion resulting in difficulties to control and monitor the reaction process. Flory and Stockmayer(F-S theory)studied it based on two fundamental assumptions:(1) independent and equivalent vinyl groups;(2) no intramolecular cyclization.However, until now its applicability to FRP of MVMs(especially regarding the extent of intramolecular cyclization) is still controversial. In this paper, Monte Carlo simulations are used to study FRP of divinyl monomers by two kinetic models:with/without cyclization models. The results of the simulations are compared with the calculated gel points based on F-S theory and the experimental data. It is found that the intramolecular cyclization has a negligible impact on the polymerization process and the gel point before gelation, which are in agreement with the prediction by F-S theory, but the effect becomes significant above the gel points.
