Poly fluorooctyl methacrylate , PFOMA

We have observed similar effects in the TREPR spectra of the polymeric radical of poly(adamantyl methacrylate) (PAMA, spectrum not shown). Earge ester side chains such as the adamantyl and fluorinated alkyl groups experience a larger amount of hydrodynamic friction than do smaller side chains such as methyl and ethyl groups.  

The polymer then undergoes slower internal rotations, and the TREPR spectrum of the main-chain radical is broadened. The similarity in the spectra from PFOMA and PAMA suggests that the conformational mobility of the polymeric radical in solution plays a major role in the intensity and spectral shape of the TREPR signal from these polymeric radicals and that side chain size and structure can completely prevent access to the fast motion limit, at least at temperatures below 135°C. Higher temperatures are not currently available to us because our high temperature flow system in limited to a maximum reservoir temperature of 150°C, for safety reasons. 

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It was previously reported that the homopolymer surfactant PFOA successfully stabilized poly(methyl methacrylate) (PMMA) dispersion polymerizations (DeSimone et al., 1994 Hsiao et ah, 1995), but was not successful for styrene dispersion polymerizations (Canelas et al., 1996). In these styrene polymerizations, the C02 pressure used was 204 bar. However, later studies showed that both PFOA and poly(l,l-dihydroper-fluorooctyl methacrylate) (PFOMA) could stabilize polystyrene (PS) particles (Shiho and DeSimone, 1999) when a higher pressure was used. These polymerizations were conducted at 370 bar, 65 °C, and the particle size could be varied from 3 to 10 pm by varying the concentration of stabilizer. These homopolymer surfactants are less expensive and easier to synthesize than block copolymer surfactants and provide access to a large range of particle sizes. 

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