the present invention relates to a process for the manufacture of pvdf homopolymer or copolymer by radical polymerization of vinylidene fluoride , 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 ) an aqueous pvdf dispersion is obtained , b ) the dispersion from stage a ) is washed , optionally after having been coagulated , to lower the proportion of possible surfactant in the pvdf to below 300 ppm , this proportion being expressed with respect to the dried pvdf , c ) sodium acetate and optionally a potassium alkylsulphonate are added to the dispersion washed in b ), d ) the dispersion from stage c ) is dried by any means to recover the pvdf powder comprising sodium acetate and optionally a potassium alkylsulphonate .