作者：Fa-Ai Zhang*, Ming Luo, Zheng-Ji Chen, Zhi-Bo Wei, Thomas J. Pinnavaia
關(guān)鍵字：mesoporous additives; emulsion polymerization; CMC; molecular weight; emulsion stability
論文來(lái)源：期刊
具體來(lái)源：polymer engineering and science
發(fā)表時(shí)間：2014年
Rod-like and spherical
mesoporous SBA-15 silica particles were synthesized as pure silicas and surface modified by organosilane coupling
agents firstly, and then the effects of these mesoporous materials
on the critical micelle concentration (CMC) of sodium
dodecylsulfate (SDS), the stabilities of batch and semi-continuous MMA emulsion
polymerizations, and the molecular weights and molecular weight distributions
of the polymer products were studied. The incorporation of both unmodified and
silane-modified forms of the mesoporous silica particles in the polymerization reaction
increased the CMC of SDS. The presence of the unmodified mesoporous silica in
the polymerization process led to instability in the batch
emulsion polymerization process, as indicated by the formation of increased amounts
of coagulum,
and a decrease in the molecular weight of the polymer product. However, in
comparison to the polymer formed in the absence of particle additives the molecular
weight of the PMMA polymer increased with the amount of emulsifier and the
addition of silane –modified SBA-15 particles, suggesting the growth of the
polymer chains is facilitated at least in part by reaction in the pores of the
particles. The improvement in molecular weight indicates that semi-continuous MMA
emulsion polymerization is best suited for the preparation of PMMA – mesoporous
silica composites