Fabrication and Characterization of Meltblown Poly(vinylidenedifluoride) Membranes
The meltblowing process may be employed to produce high volume of nonwoven poly(vinylidene difluoride) (PVDF) mats with fine fibers that lead to small pores. Although significant research has been reported on electrospinning of PVDF, there are no studies reported on the formation and characterization of PVDF meltblown mats because of the technological barriers associated with meltblowing the polymer. We investigated the fundamental properties and characteristics of experimental grade melt blowable PVDF (Kynar resin RC 10,287, Arkema, Inc. with the objective of elucidating the structure property process relationships of the meltblown mats. We have produced high quality meltblown PVDF mats with a low solid volume fraction (as low as 22% and an average fiber diameter varying from 2 to 6 mm. The electrochemical resistance and absorbance capacity (electrolyte uptake up to 200% of meltblown PVDF make it suitable for battery separator applications. We show that interactions of the meltblown PVDF with the electrolyte lead to a morphology change in the fibers and a 3% decrease in crystallinity. Using cutting edge meltblowing technologies, meltblown PVDF could become the separator in next generation Li ion batteries.