| Summary: | 碩士 === 逢甲大學 === 化學工程學所 === 92 === Poly(t-butyl acrylate) (PtBA) sample with molecular weights (Mw) of 20,000 and 120,000 were prepared by anionic polymerization, respectively. The PtBA samples were further hydrolyzed into polyacrylic acid (PAA) in DMF solvent in the presence of p-toluenesulfonic acid (PTSA), and converted to sodium salt. The Poly(sodium acrylate) (PANa) has been determined the interfacial properties and used as the emulsifier in the emulsion polymerization of styrene. The chemical structures of the PtBA, PAA snd PANa have been analyzed by using FTIR.
The data of critical micelle concentration (CMC) of PANa for MW of 20,000 and 120,000 were 4.5 and 3.8 (g/L), respectively. They exhibited some suspension stability, but poor in emulsion stability. The emulsion polymerization of styrene using PANa as the single-surfactant has a very low polymerization rate and a ten-fold larger average particle dimeter than that using a mixture of PANa and sodium dodecyl sulfate (SDS). The average radical number per particle is far larger than 0.5 for the single-surfactant systen, which produce polystyrene of MW lower than 100,000, lower than the MW usually observed in emulsion polymerization.
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