The present invention relates to a process for the manufacture of PVDF homopolymer
or copolymer by radical polymerization of vinylidene fluoride (VDF), and optionally
of a comonomer, in aqueous dispersion and in the presence of a transfer agent,
of a persulphate as radical initiator, optionally of a surface-active additive
and optionally of a paraffin wax, in which:
- a) sodium acetate is added, either at the start of or during or after
the polymerization,
- b) a potassium alkylsulphonate is optionally added after the polymerization,
- c) an aqueous PVDF dispersion is obtained,
- d) the PVDF is collected by atomizing the dispersion obtained in c)
with air at a temperature of between 120 and 220 C., the aqueous dispersion
obtained in c) not being washed with water before atomizing.
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