Particle formation in the soapless emulsion copolymerization of vinylidene fluoride and hexafluoropropene

✍ Scribed by Bonardelli, Piergiorgio ;Moggi, Giovanni ;Russo, Saverio

• Publisher: Wiley (John Wiley & Sons)
• Year: 1985
• Weight: 380 KB
• Volume: 10
• Category: Article
• ISSN: 0025-116X
• DOI: 10.1002/macp.1985.020101985104

✦ Synopsis

The comonomer system based on vinylidene fluoride (VDF) and hexafluoropropene (HFP) has been polymerized in soapless emulsion, at various pressures of the gaseous feed and different concentrations of the free-radical initiator. The particle size and number, evaluated as a function of conversion, suggest a rather long nucleation period. In Smith-Ewart's Interval I1 the limiting particle number decreases with increasing monomer fugacity (which is proportio_ nal to the monomer concentration in water), and incre ases with increasing initiator concentration. The kinetic data cannot be fully accounted for by changes of particle number. On the contrary, there is evidence that the average number of free radicals per particle is affected by experimental conditions and follows a trend very similar to that predic ted by Stockmayer's model.